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 ...

Survival data were simulated under the Weibull model in a half-sib family design, and about 50% of the records were censored. The data were analysed using the proportional hazard model (PHM) and, after transformation to survival scores, using a linear and a binary (logit) model (LIN and BIN, respectively), where the survival scores are indicators of survival during time period t given survival ...

For complex systems, such as the aircraft, the implementation of prognostics and health management (PHM) techniques can effectively improves the system performance and achieves the required reliability, safety and supportability. Traditionally, the design of the PHM system and the aircraft is often implemented separately and sequentially, which is not optimal in the view of the whole aircraft s...

Hedge funds have the most sophisticated risk management practices; however, hedge funds also appear to have a short lifetime relative to other managed funds. In this study, we investigate the failure probabilities of hedge funds—particularly the failures due to financial distress. We forecast the failure probabilities of hedge funds using both a proportional hazard model and a logistic model. B...

background: the aim of this study was to detect prognostic factors in recurrent breast cancer metastasis. materials and methods: th is retrospective cohort study employed data from 996 breast cancer patients of isfahan seyed-o-shohada research center from 1998 to 2010. stratifi ed cox proportional hazards model, marginal approach, was used to evaluate the prognostic value of estrogen receptor, ...

It is assumed for the Cox’s proportional hazards model that the survival times of subjects are independent. This assumption might be violated in some situations, in which the collected data are correlated. The well-known Cox model is not valid in this situation because independence assumption among individuals is violated. For this purpose Cox’s proportional hazard model is extent to the analys...

objective: tempo is the average waiting time to next birth for a woman. role of fertility as the most important phenomenon determining population fluctuations due to the studies of it compared with other demographic phenomena be important and review the multifarious socioeconomic factors of it share  a large effective population studies. general purpose of this study is fitting the cox model to...

This article investigates the value of perfect monitoring information for optimal replacement of deteriorating systems in the Proportional Hazards Model (PHM). A continuous-time Markov chain describes the condition of the system. Although the form of an optimal replacement policy for system under periodic monitoring in the PHM was developed previously, an approximation of the Markov process as ...