Simulation studies present an important statistical tool to investigate the performance, properties and adequacy of statistical models in pre-specified situations. One of the most important statistical models in medical research is the proportional hazards model of Cox. In this paper, techniques to generate survival times for simulation studies regarding Cox proportional hazards models are pres...

the cold climate is a favorable parameter for the development of tension cracks and decrease of rock brittleness. therefore, this paper attempts to investigate the hamekasi porous limestone in order to predict the brittleness indices during freeze-thaw cycles. the freeze–thaw test was executed for one cycle including 16 h of freezing, and 8 h of thawing. the geo mechanical properties and brittl...

We consider the problem of measurements made by several laboratories (or methods) on virtually the same object of interest. In general, the number of measurements made at each laboratory may differ. Moreover, the laboratories may exhibit the between-laboratory variability caused by the systematic error due to each laboratory, as well as different within-laboratory variances caused by different ...

The statistical methodology for the design and analysis of clinical Phase II dose-response studies, with related software implementation, is well developed for the case of a normally distributed, homoscedastic response considered for a single timepoint in parallel group study designs. In practice, however, binary, count, or time-to-event endpoints are encountered, typically measured repeatedly ...

introduction: the framework convention tobacco control (fctc) is designed by world health organization (who), in response to the globalization of the tobacco epidemic, in 2003. all treaty signatories including iran adopted to perform it during 3 years. this study was performed to design a model for evaluation of the implementation of this treaty in iran. methods: this study was a qualitative st...

The motivation for this work is to propose a first thorough review of dough rheological models used in numerical applications. Although many models have been developed to describe dough rheological characteristics, few of them are employed by researchers in numerical applications. This article reviews them in detail and attempts to provide new insight into the use of dough rheological models.

background: in modern life, the incidence of traumatic injuries increases daily. in accidents which lead to trauma, massive bleeding is the main cause of death. nowadays, many different chemical and herbal agents are available for quick control of bleeding. objectives: in this study, we compare the effectiveness of two different types of chemical agents for control of bleeding in an animal mode...

We developed a new semi-supervised EM-like algorithm that is given the set of objects present in eachtraining image, but does not know which regions correspond to which objects. We have tested thealgorithm on a dataset of 860 hand-labeled color images using only color and texture features, and theresults show that our EM variant is able to break the symmetry in the initial solution. We compared...

the main objective of this article is to present a comparative study of capital assets pricing models (capm) with extrapolating capital assets pricing models (x-capm) of companies admitted in tehran exchange market which is accomplished for the first time by investigators of this research in iran. accordingly, the statistical population under study of this research includes all companies admitt...