background: one of the main problems of dedicated iort accelerators is to determine dosimetric characteristics of the electron beams. monte carlo simulation of iort accelerator head and produced beam will be useful to improve the accuracy of beam dosimetry. materials and methods: liac accelerator head was modeled using the beamnrcmonte carlo simulation system. phase-space files were generated a...

background: making use of the orthovoltage machines in radiotherapy, is one of the routine methods for the treatment of the superficial lesions. in this study, an important determinant of x-ray quality, the hvl (half value layer), has been evaluated. materials and methods: the hvls of a orthovoltage x-ray machine in 120 and 180 kvp are measured, using an empirical method, in which the hvls are ...

background: for an effective treatment planning in brachytherapy, it is necessary to know the accurate source dosimetric information such as air kerma strength, exposure rate constant, dose rate constant and redial dose distribution. the usual method to determine these factors is thermo luminescent dosimeter (tld) dosimetry. nowadays, another more accurate method is known to be the monte carlo ...

The Dirichlet process, introduced by T. Ferguson in 1973, is the most famous and successful example of discrete nonparametric prior in Bayesian statistics. Among many desirable features, such process is posterior consistent, that is the posterior distribution accumulates, as the sample size grows to infinity, to a mass point at the “true” distribution, say P0, that has generated the data, whate...

First, the normalizing denominator in the Bayes’s Rule often has a form of integral which is typically intractable. Second, we often want an estimate of the posterior, for example the mean, the standard deviation, etc. And this estimation can be reduced to calculating integrals of the form. Monte Carlo methods can be applied to this integral computation g(θ)f(θ)λ(dθ) with high-dimensional param...

For both the academic and the financial communities it is a familiar stylized fact that stock market returns have negative skewness and excess kurtosis. This stylized fact has been supported by a vast collection of empirical studies. Given that the conventional measures of skewness and kurtosis are computed as an average and that averages are not robust, we ask, “How useful are the measures of ...

A new method to estimate the variance of an RQMC estimate has been proposed. It is expected that this method will be computationally inexpensive and will produce quite accurate estimates for a wide range of integrands. This is a ’proof of concept ’ work and therefore in its early stages.

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In this paper, we present the results of Monte Carlo simulations for two popular techniques of longrange correlations detection – classical and modified rescaled range analyses. A focus is put on an effect of different distributional properties on an ability of the methods to efficiently distinguish between short and long-term memory. To do so, we analyze the behavior of the estimators for inde...