abstract background: keratoconus is a bilateral corneal disease, which one way to cure it is to transplant. the transplantation may be rejected by recipient's immune system, which leads to failure of the graft. this study aimed to analysis the factors affecting bilateral corneal graft rejection based on copula function. methods: a sample of bilateral graft rejection times was assessed. since co...

in spite of the fact that the principles of impinging stream reactors have been developed for more than half a century, the performance analysis of such devices, from the viewpoint of the mathematical modeling, has not been investigated extensively. in this study two mathematical models were proposed to describe particulate matter drying in tangential impinging stream dryers. the models were de...

with recent developments in communication technologies, it is possible to access information any time and in any place; however, mobile environments bring forward certain requirements and exclusive challenges including low connection speeds and bandwidth limitations. thus, we need to consider mobile limitations when using web services. providing services and limited resource allocation to users...

growing amount of information on biological sequences has made application of statistical approaches necessary for modeling and estimation of their functions. in this paper, sensitivity and specificity of the first and second markov chains for prediction of genes was evaluated using the complete double stranded  dna virus. there were two approaches for prediction of each markov model parameter,...

there are some problems with estimating the time required for the manufacturing process of products, especially when there is a variable serving time, like control stage. these problems will cause overestimation of process time. layout constraints, reworking constraints and inflexible product schedule in multi product lines need a precise planning to reduce volume in particular situation of lin...

in this paper at rst, a history of mathematical models is given.next, some basic information about random variables, stochastic processesand markov chains is introduced. as follows, the entropy for a discrete timemarkov process is mentioned. after that, the entropy for sis stochastic modelsis computed, and it is proved that an epidemic will be disappeared after a longtime.

In this paper an approximation for entropy rate of an ergodic Markov chain via sample path simulation is calculated. Although there is an explicit form of the entropy rate here, the exact computational method is laborious to apply. It is demonstrated that the estimated entropy rate of Markov chain via sample path not only converges to the correct entropy rate but also does it exponential...