The class of second-order curvilinear gratings consists of all the curvilinear gratings that are obtained by second-order spatial transformations of periodic gratings. It includes, for example, circular, elliptic, and hyperbolic gratings as well as circular, elliptic, and hyperbolic zone plates. Such structures occur quite frequently in optics, and their Fourier transforms may arise, for instan...

The Radon transform is a fundamental tool in many areas. For example, in reconstruction of an image from its projections (CT scanning). Recently A. Averbuch et al. [SIAM J. Sci. Comput., submitted for publication] developed a coherent discrete definition of the 2D discrete Radon transform for 2D discrete images. The definition in [SIAM J. Sci. Comput., submitted for publication] is shown to be ...

Single image deblurring aims to restore a sharp by removing blurred areas in the single image. Such images are not only visually unpleasant, but cause various problems many applications like recognition. In recent years, with development of deep learning, neural networks used deblurring. Especially, encoder-decoder structures widely for and successfully high quality images. However, FLOPs numbe...

The general purpose of the technical protection system and its composition are shown. necessity using security systems at objects information activity has been determined. existing method transmitting in loop is analyzed, shortcomings It proposed to use digital methods processing order counteract shortcomings.

Orthogonal Time Frequency Space (OTFS) modulation is a recently proposed scheme for time-varying narrowband channels in terrestrial radio-frequency communications. Underwater acoustic (UWA) and ultra-wideband (UWB) communication systems, on the other hand, confront wideband channels. Unlike channels, which time contractions or dilations due to Doppler effect can be approximated by frequency-shi...