background : gastric cancer is the one of the most prevalent reason of cancer-related death in the world. survival of patients after surgery involves identifying risk factors. there are various models to detect the effect of risk factors on patients’ survival. the present study aims at evaluating these models. methods : data from 330 gastric cancer patients diagnosed at the iran cancer institut...

tires represent a critical spare part in mines. there is a shortage of medium and large tires. in addition, with increased mining activities and the creation of new mines, the demand for tires has increased significantly. thus, it is particularly important for mining engineers to identify tire characteristics and correctly manage the spare part inventory. spare parts management is critical from...

background : the aim of this study was to predict the survival rate of iranian gastric cancer patients using the cox proportional hazard and artificial neural network models as well as comparing the ability of these approaches in predicting the survival of these patients. methods: in this historical cohort study, the data gathered from 436 registered gastric cancer patients who have had surgery...

background: although the cox proportional hazard regression is the most popular model for analyzing the prognostic factors on survival of cancer patients, under certain circumstances, parametric models estimate the parameter more efficiently than the cox model.  the aim of this study was to compare the cox regression model  with parametric models in patients with gastric cancer who registered a...

the waiting time between children births are called tempo. this phenomenon plays a crucial role in the child and mother health. the purpose of the present study is determination of factors which influence this variable of interest. a significance level of 5% and power of 80% considered to calculate the required sample size for this cross sectional study. the sample size of 124 women determined ...

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...

background: cox proportional hazard (cph) model is the most widely used model for survival analysis. when there are unobserved/unmeasured individuals factor, then the results of the cox proportional hazard model may not be reliable. the purpose of this study was to compare the results of cph and frailty models in breast cancer (bc) patients. methods: a historical cohort study was carried out us...