Hamdullah Şevli

Stability of Pexiderized quadratic functional equation in intuitionistic fuzzy normed space

The object of the present paper is to determine the stability of the Hyers-Ulam-Rassias type theorem concerning the Pexiderized quadratic functional equation in intuitionistic fuzzy normed spaces (IFNS).

Intuitionistic fuzzy stability of a Jensen functional equation via fixed point technique

The object of this paper is to determine Hyers-Ulam-Rassias stability concerning the Jensen functional equation in intuitionistic fuzzy normed space (IFNS) by using the fixed point method. Further, we establish stability of the Cauchy functional equation in IFNS.

Complete monotonicity results for some functions involving the gamma and polygamma functions

In this paper we prove new complete monotonicity properties of some functions involving the gamma function. As consequences of them we establish various new upper and lower bounds for the gamma function and the harmonic numbers.

Power series method and approximate linear differential equations of second order

In this paper, we will establish a theory for the power series method that can be applied to various types of linear differential equations of second order to prove the Hyers-Ulam stability.MSC:34A05, 39B82, 26D10, 34A40.

Some further extensions of absolute Cesàro summability for double series

In a recent paper [Savaş and Rhoades in Appl. Math. Lett. 22:1462-1466, 2009], the authors extended the result of Flett [Proc. Lond. Math. Soc. 7:113-141, 1957] to double summability. In this paper, we consider some further extensions of absolute Cesàro summability for double series.MSC:40F05, 40G05.

On the perturbation of Volterra integro-differential equations

Abstract In this work, we will prove that every solution of a perturbed Volterra integro-differential equation can be approximated by a solution of the Volterra integro-differential equation.

On double Hausdorff summability method

Das (Proc. Camb. Philos. Soc. 67:321-326, 1970) proved that every conservative Hausdorff matrix is absolutely k th power conservative. Savaş and Rhoades (Anal. Math. 35:249-256, 2009) proved the result of Das for double Hausdorff summability. In this paper we will consider the double Endl-Jakimovski (E-J) generalization and we will prove the corresponding result of Savaş and Şevli (J. Comput. Anal. Appl. 11:702-710, 2009) for double E-J generalized Hausdorff matrices.MSC:40F05, 40G05.

On general summability factor theorem of infinite series

Abstract A lower triangular matrix with nonzero principal diagonal entries is called a triangle. In this paper we obtain the sufficient conditions for ∑ a n λ n to be summable ∣ A ∣ k whenever ∑ a n is summable ∣ T ∣ k for a triangle T .

On Asymptotically Open image in new window-Statistical Equivalent Sequences of Fuzzy Numbers

The goal of this paper is to give the asymptotically -statistical equivalent which is a natural combination of the definition for asymptotically equivalent, invariant mean and -statistical convergence of fuzzy numbers.

On Asymptotically -Statistical Equivalent Sequences of Fuzzy Numbers

The goal of this paper is to give the asymptotically -statistical equivalent which is a natural combination of the definition for asymptotically equivalent, invariant mean and -statistical convergence of fuzzy numbers.