Various investigators such as Khan 1974 , Chandra 2002 , and Liendler 2005 have determined the degree of approximation of 2π-periodic signals functions belonging to Lip α, r class of functions through trigonometric Fourier approximation using different summability matrices with monotone rows. Recently, Mittal et al. 2007 and 2011 have obtained the degree of approximation of signals belonging to...

A triangle is a lower triangular matrix with all principal diagonal entriesbeing nonzero. Given an almost increasing sequence {Xn} and a sequence {λn} satisfying certain conditions, we obtain sufficient conditions for the series ∑ anλn to be absolutely summable of order k ≥ 1 by a triangle T . As a corollary we obtain the corresponding result when T is a weighted mean matrix. Theorem 1 of this ...

Abstract The order of integration is valid to characterize linear processes; but it is not appropriate for non-linear worlds. We propose the concept of summability (a re-scaled partial sum of the process being Op(1)) to handle non-linearities. The paper shows that this new concept, S (δ): (i) generalizes I (δ); (ii) measures the degree of persistence as well as of the evolution of the variance;...

We prove a general theorem on |N̄,pn;δ|k summability factors, which generalizes a theorem of Bor (1994) on |N̄,pn|k summability factors, under weaker conditions by using an almost increasing sequence. 2000 Mathematics Subject Classification. Primary 40D15, 40F05, 40G99.

in this paper‎, ‎following a very recent‎ ‎and new approach‎, ‎we further generalize recently introduced‎ ‎summability methods‎, ‎namely‎, ‎$i$-statistical convergence and‎ ‎$i$-lacunary statistical convergence (which extend the important‎ ‎summability methods‎, ‎statistical convergence and lacunary‎ ‎statistical convergence using ideals of $mathbb{n}$) and‎ ‎introduce the notions of $i$-statis...

We define weighted mean summability method of double sequences in intuitionistic fuzzy normed spaces(IFNS), and obtain necessary sufficient Tauberian conditions under which convergence IFNS follows from their summability. This study reveals also results for some known summation methods the special cases.

In this paper, we introduce the notions of [V,λ ]-summability and λ−statistical convergence of function by taking a nonnegative real-valued Lebesque measurable function in the interval (1,∞) and introduce new notions, namely, [V,λ ] (I )− summability, and Iλ−statistical convergence of function. We mainly examine the relation between these two new methods.

In this paper, we introduce the concept of λ-statistical convergence in n-normed spaces. Some inclusion relations between the sets of statistically convergent and λ-statistically convergent sequences are established. We find its relations to statistical convergence, (C,1)-summability and strong (V, λ)-summability in n-normed spaces.

In this paper, we introduce the concepts of weighted ideal statistical convergence or SN (I)-convergence and I − (N, pn)-summability. We also establish the relations between our new methods. Further, we determine a Korovkin type approximation theorem through I − (N, pn)-summability. −−−−−−−−−−−−−−−−−−−−−−−−−−−−

In this paper, we establish a new theorem on | A, pn |k summability factors of Fourier series using matrix transformation, which generalizes a main theorem of Bor [6] on ∣∣N̄, pn∣∣k summability factors of Fourier series. Also some new results have been obtained.