@Article{Yankson2017,
author="Yankson, Ernest",
title="Stability Results for Neutral Integro-Differential Equations with Multiple Functional Delays",
journal="Khayyam Journal of Mathematics",
year="2017",
volume="3",
number="1",
pages="1-11",
abstract="Necessary and sufficient conditions for the zero solution of the nonlinear neutral integro-differential equation\begin{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.",
issn="2423-4788",
doi="10.22034/kjm.2017.43831",
url="http://www.kjm-math.org/article_43831.html"
}
@Article{Ardjouni2017,
author="Ardjouni, Abdelouaheb
and Nouioua, Farid
and Djoudi, Ahcene",
title="Periodic Solutions for Third-Order Nonlinear Delay Differential Equations with Variable Coefficients",
journal="Khayyam Journal of Mathematics",
year="2017",
volume="3",
number="1",
pages="12-21",
abstract="In this paper, the following third-order nonlinear delay differential equationwith periodic coefficients%\begin{align*}& x^{\prime\prime\prime}(t)+p(t)x^{\prime\prime}(t)+q(t)x^{\prime}(t)+r(t)x(t)\\& =f\left( t,x\left( t\right) ,x(t-\tau(t))\right) +\frac{d}{dt}g\left(t,x\left( t-\tau\left( t\right) \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.",
issn="2423-4788",
doi="10.22034/kjm.2017.44493",
url="http://www.kjm-math.org/article_44493.html"
}
@Article{Wójcik2017,
author="Wójcik, Paweł",
title="Operators Reversing Orthogonality and Characterization of Inner Product Spaces",
journal="Khayyam Journal of Mathematics",
year="2017",
volume="3",
number="1",
pages="22-24",
abstract="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.",
issn="2423-4788",
doi="10.22034/kjm.2017.44746",
url="http://www.kjm-math.org/article_44746.html"
}
@Article{Varma2017,
author="Varma, S.Sunil
and Rosy, Thomas",
title="Certain Properties of a Subclass of Univalent Functions With Finitely Many Fixed Coefficients",
journal="Khayyam Journal of Mathematics",
year="2017",
volume="3",
number="1",
pages="25-32",
abstract="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.",
issn="2423-4788",
doi="10.22034/kjm.2017.44920",
url="http://www.kjm-math.org/article_44920.html"
}
@Article{YükselPerktaş2017,
author="Yüksel Perktaş, Selcen",
title="On Para-Sasakian Manifolds Satisfying Certain Curvature Conditions with Canonical Paracontact Connection",
journal="Khayyam Journal of Mathematics",
year="2017",
volume="3",
number="1",
pages="33-43",
abstract="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.",
issn="2423-4788",
doi="10.22034/kjm.2017.45190",
url="http://www.kjm-math.org/article_45190.html"
}
@Article{Kajla2017,
author="Kajla, Arun",
title="Approximation for a Summation-Integral Type Link Operators",
journal="Khayyam Journal of Mathematics",
year="2017",
volume="3",
number="1",
pages="44-60",
abstract="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.",
issn="2423-4788",
doi="10.22034/kjm.2017.45322",
url="http://www.kjm-math.org/article_45322.html"
}
@Article{Meftah2017,
author="Meftah, Badreddine",
title="Ostrowski's Inequality for Functions whose First Derivatives are $s$-Preinvex in the Second Sense",
journal="Khayyam Journal of Mathematics",
year="2017",
volume="3",
number="1",
pages="61-80",
abstract="In this paper, we establish some new Ostrowski type inequalities forfunctions whose first derivatives are $s$-preinvex in the second sense.",
issn="2423-4788",
doi="10.22034/kjm.2017.46863",
url="http://www.kjm-math.org/article_46863.html"
}
@Article{Lerkchaiyaphum2017,
author="Lerkchaiyaphum, Kritsada
and Phuengrattana, Withun",
title="Proximal Point Algorithms for Numerical Reckoning Fixed Points of Hybrid-Type Multivalued Mappings in Hilbert Spaces",
journal="Khayyam Journal of Mathematics",
year="2017",
volume="3",
number="1",
pages="81-89",
abstract="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.",
issn="2423-4788",
doi="10.22034/kjm.2017.46951",
url="http://www.kjm-math.org/article_46951.html"
}