due to damaging effects of speckle noise to information of radar images, reduction of these effects has been considered by many researchers. we discussed speckle reduction of radar images based on curvelet transformation. more specifically we discussed the speckle reduction with emphasizing on preservation of the edges by hard thresholding of curvelet transformation. in this algorithm, first mu...

the effect of underground cavities in site seismic response was studied over the subway tunnels that are under construction in the city of karaj, using ambient noise measurements as well as numerical modeling. the idea for this research comes from the observation of differences in experimental site transfer function, calculated on more than 100 locations of the city, for the areas near the unde...

background and aim: spatial hearing is one of the most important functions of binaural hearing processing that is based on detection of fine interaural time and interaural intensity difference. spatial hearing is beyond auditory localization and lateralization. it helps auditory scene analysis and target stream segregation from other simultaneous sound sources. this function is important in spe...

background: electronic portal imaging devices (epids) play an important role in radiation therapy portal imaging, geometric and dosimetric verifications. a successful utilization of epids for imaging and dosimetric purposes requires a reliable quality control process routine to be carried out regularly. in this study, two in-house phantoms were developed and analyzed for implementation in a qua...

A very low voltage 9th order linear phase baseband switched capacitor (SC) filter has been designed to be used as part of a cellular GSM (Global System Mobile) receiver. A Gaussian-to-6dB filter of the order of seven is chosen and a second order function is added to reduce the group delay variations around. The filter uses a fully differential topology to increase the dynamic range and reduce t...

Removing noise from images is a challenging problem in digital image processing. This paper presents an image denoising method based on a maximum a posteriori (MAP) density function estimator, which is implemented in the wavelet domain because of its energy compaction property. The performance of the MAP estimator depends on the proposed model for noise-free wavelet coefficients. Thus in the wa...

Background: Formaldehyde (FA) is a member of aldehyde family with a simplest organic molecule, used in various industries. Since there is simultaneous exposure of formaldehyde and noise for workers in most of the workplaces and that noise can reinforce the harmful effects of some chemical pollutants. This study aimed to investigate the effects of simultaneous formaldehyde and noise exposure on ...