A BMO-estimation of two-dimensional Walsh-Fourier series is proved from which an almost everywhere exponential summability of quadratic partial sums of double Walsh-Fourier series is derived.

Zhizhiashvili proved sufficient condition for the Cesáro summability by negative order of N-multiple trigonometric Fourier series in the space L, 1 ≤ p ≤ ∞. In this paper we show that this condition cannot be improved .

In this paper we have improved the result of Bor [Bull. Math. Anal. Appl.1, (2009), 15-21] on local property of N, pn, θn k summability of factored Fourier series by proving under weaker conditions.

In this paper we prove the local L s regularity (where s depends on the summability of the data) for local " unbounded " weak solutions of a class of nonlinear parabolic equations including the p-Laplacian equation.

In this paper we prove a theorem concerning the relative strength of \R,P„\k and \R,qn\k summability methods, k > 1 , that generalizes a result of Bosanquet [1].

In this paper the concept of strongly (λM )p − Cesáro summability of a sequence of fuzzy numbers and strongly λM− statistically convergent sequences of fuzzy numbers is introduced. Keywords—Fuzzy numbers, statistical convergence, Orlicz space, gai sequence.

Abstract The main purpose of this paper is to use a power series summability method study some approximation properties Kantorovich type Szász–Mirakyan operators including Sheffer polynomials. We also establish Voronovskaya result.