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 discuss properties of convergence for a modification of the q-Bernstein operators. Using the notion of A-statistical approximation, where A is a nonnegative regular summability matrix, we investigate the Korovkin type statistical approximation properties of this modification via A-statistical approximation. For 0 < q ≤ 1, we obtain that the q-Bernstein operators is A-statistic...

Correspondence: [email protected]. ac.jp Department of Information Science, Okayama University of Science, 1-1 Ridai-chyo, Kitaku, Okayama 700-0005, Japan Abstract The purpose of this article is to discuss the existence of pseudo almost periodic solutions of linear Volterra equation: x(n + 1) = A(n)x(n) + ∑n s=−∞ F(n, s)x(s) + p(n) , n Î Z, by using an exponentially stable of the zero solution, wh...

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, a main theorem dealing with | C, 1 |k summability factors has been generalized under more weaker conditions for | C,α, β |k summability factors. This theorem also includes some new results. Mathematics Subject Classification 2000: 40D15, 40F05, 40G05, 40G99.

In this paper we extend concepts of statistical limit superior and inferior (as introduced by Fridy and Orhan) to I−limit superior and inferior and give some I−analogue of properties of statistical limit superior and inferior for a sequence of real numbers. Also we extend the concept of the statistical core to I−core for a complex number sequence and get necessary conditions for a summability m...

*Correspondence: [email protected] Department of Mathematics, İstanbul Commerce University, Sütlüce/Beyoğlu, İstanbul, Turkey Abstract Das (Proc. Camb. Philos. Soc. 67:321-326, 1970) proved that every conservative Hausdorff matrix is absolutely kth power conservative. Savaş and Rhoades (Anal. Math. 35:249-256, 2009) proved the result of Das for double Hausdorff summability. In this paper we...

Introduction. This note investigates an apparent generalization of unconditionally convergent series ^ x » in weakly complete Banach spaces. A series of elements with Xi in E is said to be unconditionally convergent if for every variation of sign €j= ± 1 , ^TMeiXi is convergent. This formulation of the definition of unconditional convergence is equivalent to that given by Orliczjé]. We call ^Xi...