The paper is devoted to the investigation of problem approximation continuous periodic functions by trigonometric polynomials, which are generated linear methods summation Fourier series.
 simplest example a partial sums their series. However, sequences not uniformly convergent over class functions. Therefore, many studies research approximative properties methods, transformations series a...

Random walks on expander graphs were thoroughly studied, with the important motivation that, under some natural conditions, these walks mix quickly and provide an efficient method of sampling the vertices of a graph. The authors of [3] studied non-backtracking random walks on regular graphs, and showed that their mixing rate may be up to twice as fast as that of the simple random walk. As an ap...

We study weighted `2 fidelity in variational models for Poisson noise related image restoration problems. Gaussian approximation to Poisson noise statistic is adopted to deduce weighted `2 fidelity. Different from the traditional weighted `2 approximation, we propose a reweighted `2 fidelity with sparse regularization by wavelet frame. Based on the split Bregman algorithm introduced in [22], th...