Gamma filter is a special class of generalized feedforward filters where feedbacks are allowed only locally. We present the conditions for the selection of optimal parameters which are the weights and the memory depth of the filter. The conditions for these two set of parameters are decoupled from each other. This allows a matched filter implementation which gives an estimate of the memory dept...

To obtain high quality of results in gamma spectrometry, it is necessary to calibrate energy and efficiency of gamma detector as accurate as possible. To achieve this aim, utilizing the convenient gamma source can be very useful. Therefore, purpose of present study was to evaluate the determined efficiency by single point gamma sources and multi-nuclides gamma source in a high purity germanium ...

We study the distribution of the durations of gamma-ray bursts (GRBs) in the unified model of short and long GRBs recently proposed by Yamazaki, Ioka, and Nakamura. Monte Carlo simulations show clear bimodal distributions, with lognormal-like shapes for both short and long GRBs, in a power-law as well as a Gaussian angular distribution of the subjets. We find that the bimodality comes from the ...

In this article, I present a method for the non-parametric (model-free) estimation of intensity pro les underlying gamma-ray bursts. The method, TIPSH, is based on applying specially calibrated thresholds to the Haar wavelet coe cients of binned counts gathered from such bursts. As functions well-localized with respect to both time and scale, wavelets are an ideal tool for working with the ofte...

Gamma Knife has become a major therapeutic method for intracranial meningiomas, vascular malformations and schwannomas with exact effect. In recent years an increasing number of delayed complications after Gamma Knife surgery have been reported, such as secondary tumors, cystic changes or cyst formation. But angiomatous lesion and delayed cyst formation after Gamma Knife for intracranial lesion...

Sometimes, when it is impossible to perform a direct measurement, it is critical to obtain an estimate of the indoor gamma dose rate with adequate accuracy and precision. With a method we set up – the IN-OUT method – it is possible to estimate the indoor gamma dose rate attributable to building materials. Gamma dose rates are measured in contact with an external wall of a dwelling, and then a “...

abstract   background : the application of du emanation for first time contaminated certain areas in the south west region of iraq after the second gulf war (1991). these contaminated areas were discovered in 1994. radioactive contamination was detected using the nuclear enterprise pcm5/1 in soil samples collected from two regions near by grazing lands. this study was done for assessment of du ...