Khayyam Journal of MathematicsKhayyam Journal of Mathematics
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Sat, 23 Sep 2017 03:38:56 +0100FeedCreatorKhayyam Journal of Mathematics
http://www.kjm-math.org/
Feed provided by Khayyam Journal of Mathematics. Click to visit.Stability Results for Neutral Integro-Differential Equations with Multiple Functional Delays
http://www.kjm-math.org/article_43831_5579.html
Necessary and sufficient conditions for the zero solution of the nonlinear neutral integro-differential equationbegin{eqnarray*}&&frac{d}{dt}Big(r(t)Big[x(t)+Q(t, x(t-g_1(t)),...,x(t-g_N(t)))Big]Big)\ &&= -a(t)x(t)+ sum^{N}_{i=1}int^{t}_{t-g_i(t)}k_i(t,s)f_i(x(s))ds end{eqnarray*} to be asymptotically stable are obtained. In the process we invert the integro-differential equation and obtain an equivalent integral equation. The contraction mapping principle is used as the main mathematical tool for establishing the necessary and sufficient conditions.Sat, 31 Dec 2016 20:30:00 +0100Approximation with Certain Szász–Mirakyan Operators
http://www.kjm-math.org/article_47347_0.html
In the current article, we consider different growth conditions for studying the well known Szász–Mirakyan operators, which were introduced in the mid-twentieth century. Here, we obtain a new approach to find the moments using the concept of moment generating functions. Further, we discuss a uniform estimate and compare convergence behavior with the recently studied one.Fri, 23 Jun 2017 19:30:00 +0100Periodic Solutions for Third-Order Nonlinear Delay Differential Equations with Variable Coefficients
http://www.kjm-math.org/article_44493_5579.html
In this paper, the following third-order nonlinear delay differential equationwith periodic coefficients%begin{align*}& x^{primeprimeprime}(t)+p(t)x^{primeprime}(t)+q(t)x^{prime}(t)+r(t)x(t)\& =fleft( t,xleft( tright) ,x(t-tau(t))right) +frac{d}{dt}gleft(t,xleft( t-tauleft( tright) right) right) ,end{align*}is considered. By employing Green's function, Krasnoselskii's fixed pointtheorem and the contraction mapping principle, we state and prove theexistence and uniqueness of periodic solutions to the third-order nonlineardelay differential equation.Sat, 31 Dec 2016 20:30:00 +0100New Inequalities of Hermite-Hadamard Type for Log-Convex Functions
http://www.kjm-math.org/article_47458_0.html
Some new inequalities of Hermite-Hadamard type for log-convex functions defined on real intervals are given.Sun, 25 Jun 2017 19:30:00 +0100Operators Reversing Orthogonality and Characterization of Inner Product Spaces
http://www.kjm-math.org/article_44746_5579.html
In this short paper we answer a question posed by Chmieliński in [Adv. Oper. Theory, 1 (2016), no. 1, 8-14]. Namely, we prove that among normed spaces of dimension greater than two,only inner product spaces admit nonzero linear operators which reverse the Birkhoff orthogonality.Sat, 31 Dec 2016 20:30:00 +0100Linear Preservers of Right SGUT-Majorization on $\mathbb{R}_{n}$
http://www.kjm-math.org/article_49229_0.html
A matrix $R$ is called a $textit{generalized row substochastic}$ (g-row substochastic) if the sum of entries on every row of $R$ is less than or equal to one. For $x$, $y in mathbb{R}_{n}$, it is said that $x$ is $textit{rsgut-majorized}$ by $y$ (denoted by $ x prec_{rsgut} y$ ) if there exists an $n$-by-$n$ upper triangular g-row substochastic matrix $R$ such that $x=yR$. In the present paper, we characterize the linear preservers and strong linear preservers of rsgut-majorization on$mathbb{R}_{n}$.Thu, 10 Aug 2017 19:30:00 +0100Certain Properties of a Subclass of Univalent Functions With Finitely Many Fixed Coefficients
http://www.kjm-math.org/article_44920_5579.html
In this paper a new class of analytic, univalent and normalized functions with finitely many fixed coefficients is defined. Properties like coefficient condition, radii of starlikeness and convexity, extreme points and integral operators applied to functions in the class are investigated.Sat, 31 Dec 2016 20:30:00 +0100A Class of Sequence Spaces Defined by Fractional Difference Operator and Modulus Function
http://www.kjm-math.org/article_49370_0.html
A class of vector-valued sequence spaces is introduced employing the fractional difference operator $Delta^{(alpha)}$, a sequence of modulus functions and a non-negative infinite matrix. Sequence spaces of this class generalize many sequence spaces which are defined by difference operators and modulus functions. It is proved that the spaces of this class are complete paranormed spaces under certain conditions. Some properties of these spaces are studied and it is shown that the spaces are not solid in general.Thu, 17 Aug 2017 19:30:00 +0100On Para-Sasakian Manifolds Satisfying Certain Curvature Conditions with Canonical Paracontact ...
http://www.kjm-math.org/article_45190_5579.html
In this article, the aim is to introduce a para-Sasakian manifold with acanonical paracontact connection. It is shown that $varphi$-conharmonically flat, $varphi $-$W_{2}$ flat and $varphi $-pseudo projectively flat para-Sasakian manifolds with respect to canonical paracontact connection are all $eta $-Einsteinmanifolds. Also, we prove that quasi-pseudo projectively flatpara-Sasakian manifolds are of constant scalar curvatures.Sat, 31 Dec 2016 20:30:00 +0100Approximation by Stancu Type Generalized Srivastava-Gupta Operators Based On Certain Parameter
http://www.kjm-math.org/article_49477_0.html
In the present paper, we introduce a Stancu type generalization of generalized Srivastava-Gupta operators based on certain parameter. We obtain the moments of the operators and then prove the basic convergence theorem. Next, the Voronovskaja type asymptotic formula and some direct results for the above operators are discussed. Also, weighted approximation and rate of convergence by these operators in terms of modulus of continuity are studied. Then, we obtain point-wise estimates using the Lipschitz type maximal function. Lastly, we propose a King type modification of these operators to obtain better estimates.Sat, 19 Aug 2017 19:30:00 +0100Approximation for a Summation-Integral Type Link Operators
http://www.kjm-math.org/article_45322_5579.html
The present article deals with the general family of summation-integral type operators. Here, we propose the Durrmeyer variant of the generalized Lupaş operators considered by Abel and Ivan (General Math. 15 (1) (2007) 21-34) and study local approximation, Voronovskaja type formula, global approximation, Lipchitz type space and weighted approximation results. Also, we discuss the rate of convergence for absolutely continuous functions having a derivative equivalent with a function of bounded variation.Sat, 31 Dec 2016 20:30:00 +0100Strong Differential Subordinations for Higher-Order Derivatives of Multivalent Analytic ...
http://www.kjm-math.org/article_50396_0.html
In the present paper, we introduce and study a new class of higher-order derivatives multivalent analytic functions in the open unit disk and closed unit disk of the complex plane by using linear operator. Also we obtain some interesting properties of this class and discuss several strong differential subordinations for higher-order derivatives of multivalent analytic functions.Thu, 21 Sep 2017 20:30:00 +0100Ostrowski's Inequality for Functions whose First Derivatives are $s$-Preinvex in the Second Sense
http://www.kjm-math.org/article_46863_5579.html
In this paper, we establish some new Ostrowski type inequalities forfunctions whose first derivatives are $s$-preinvex in the second sense.Sat, 31 Dec 2016 20:30:00 +0100Proximal Point Algorithms for Numerical Reckoning Fixed Points of Hybrid-Type Multivalued ...
http://www.kjm-math.org/article_46951_5579.html
In this paper, we propose a new iteration process to approximateminimizers of proper convex and lower semi-continuous functions andfixed points of $lambda$-hybrid multivalued mappings in Hilbertspaces. We also provide an example to illustrate the convergencebehavior of the proposed iteration process and numerically comparethe convergence of the proposed iteration scheme with the existingschemes.Sat, 31 Dec 2016 20:30:00 +0100