Khayyam J. Math. Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) Khayyam Journal of Mathematics 2423-4788 Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) 124 10.22034/kjm.2017.43831 34 Ordinary differential equations Stability Results for Neutral Integro-Differential Equations with Multiple Functional Delays Yankson Ernest Department of Mathematics and Statistics, University of Cape Coast, Cape Coast, Ghana. 01 01 2017 3 1 1 11 06 12 2016 01 03 2017 Copyright © 2017, Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures). 2017 http://www.kjm-math.org/article_43831.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.

Stability integro-differential equation functional delay
Khayyam J. Math. Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) Khayyam Journal of Mathematics 2423-4788 Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) 124 10.22034/kjm.2017.44493 34 Ordinary differential equations Periodic Solutions for Third-Order Nonlinear Delay Differential Equations with Variable Coefficients Third-Order Nonlinear Delay Differential Equations Ardjouni Abdelouaheb Department of Mathematics and Informatics, University of Souk Ahras, P.O. Box 1553, Souk Ahras, 41000, Algeria. Nouioua Farid Department of Mathematics and Informatics, University of Souk Ahras, P.O. Box 1553, Souk Ahras, 41000, Algeria. Djoudi Ahcene Department of Mathematics, University of Annaba, P.O. Box 12, Annaba, 23000, Algeria. 01 01 2017 3 1 12 21 16 11 2016 22 03 2017 Copyright © 2017, Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures). 2017 http://www.kjm-math.org/article_44493.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.

fixed point periodic solutions third-order nonlinear delay differential equations
Khayyam J. Math. Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) Khayyam Journal of Mathematics 2423-4788 Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) 124 10.22034/kjm.2017.44746 15 Linear and multilinear algebra; matrix theory 46 Functional analysis 47 Operator theory Operators Reversing Orthogonality and Characterization of Inner Product Spaces Operators Reversing Orthogonality Wójcik Paweł Institute of Mathematics, Pedagogical University of Cracow, Podchorążych 2, 30-084 Kraków, Poland. 01 01 2017 3 1 22 24 25 01 2017 07 04 2017 Copyright © 2017, Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures). 2017 http://www.kjm-math.org/article_44746.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.

Birkhoff orthogonality orthogonality reversing mappings characterizations of inner product spaces
Khayyam J. Math. Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) Khayyam Journal of Mathematics 2423-4788 Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) 124 10.22034/kjm.2017.44920 30 Functions of a complex variable Certain Properties of a Subclass of Univalent Functions With Finitely Many Fixed Coefficients Certain Properties of a Subclass of Univalent Functions Varma S.Sunil Department of Mathematics, Madras Christian College, Tambaram, Chennai-600059, Tamil Nadu, India Rosy Thomas Department of Mathematics, Madras Christian College, Tambaram, Chennai-600059, Tamil Nadu, India 01 01 2017 3 1 25 32 11 01 2017 10 04 2017 Copyright © 2017, Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures). 2017 http://www.kjm-math.org/article_44920.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.

Analytic function univalent function fixed coefficient Extreme point
Khayyam J. Math. Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) Khayyam Journal of Mathematics 2423-4788 Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) 124 10.22034/kjm.2017.45190 53 Differential geometry On Para-Sasakian Manifolds Satisfying Certain Curvature Conditions with Canonical Paracontact Connection On Para-Sasakian Manifolds Yüksel Perktaş Selcen Faculty of Arts and Science, Department of Mathematics, Adıyaman University, Adıyaman, Turkey 01 01 2017 3 1 33 43 20 09 2016 28 04 2017 Copyright © 2017, Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures). 2017 http://www.kjm-math.org/article_45190.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.

Canonical connection paracontact metric structure normal structure
Khayyam J. Math. Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) Khayyam Journal of Mathematics 2423-4788 Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) 124 10.22034/kjm.2017.45322 39 Difference and functional equations 44 Integral transforms, operational calculus 46 Functional analysis Approximation for a Summation-Integral Type Link Operators Approximation for a summation-integral type link operators Kajla Arun Department of Mathematics, Central University of Haryana, Haryana-123031, India. 01 01 2017 3 1 44 60 01 04 2017 03 05 2017 Copyright © 2017, Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures). 2017 http://www.kjm-math.org/article_45322.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.

Global approximation Rate of convergence Modulus of continuity bounded variation
Khayyam J. Math. Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) Khayyam Journal of Mathematics 2423-4788 Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) 124 10.22034/kjm.2017.46863 26 Real functions Ostrowski's Inequality for Functions whose First Derivatives are \$s\$-Preinvex in the Second Sense Ostrowski's Inequality for Functions whose First Derivatives Meftah Badreddine Laboratoire des t&#039;el&#039;ecommunications, Facult&#039;e des Sciences et de la Technologie, University of 8 May 1945 Guelma, P.O. Box 401, 24000 Guelma, Algeria. 01 01 2017 3 1 61 80 02 04 2017 14 06 2017 Copyright © 2017, Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures). 2017 http://www.kjm-math.org/article_46863.html

In this paper, we establish some new Ostrowski type inequalities forfunctions whose first derivatives are \$s\$-preinvex in the second sense.

Ostrowski inequality midpoint inequality H"{o}lder inequality power mean inequality preinvex functions \$s\$-preinvex functions
Khayyam J. Math. Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) Khayyam Journal of Mathematics 2423-4788 Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures) 124 10.22034/kjm.2017.46951 47 Operator theory 65 Numerical analysis Proximal Point Algorithms for Numerical Reckoning Fixed Points of Hybrid-Type Multivalued Mappings in Hilbert Spaces Proximal Point Algorithms of Hybrid-Type Multivalued Mappings Lerkchaiyaphum Kritsada Department of Mathematics, Faculty of Science and Technology, Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand. Phuengrattana Withun Research Center for Pure and Applied Mathematics, Research and Development Institute, Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand. 01 01 2017 3 1 81 89 30 03 2017 17 06 2017 Copyright © 2017, Tusi Mathematical Research Group (TMRG) and Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with The Center of Excellence in Analysis on Algebraic Structures). 2017 http://www.kjm-math.org/article_46951.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.

Proximal point algorithm hybrid multivalued mapping Ishikawa iteration S-iteration Hilbert spaces