Department of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47885120190101On a Classification of Almost $\alpha $-Cosymplectic Manifolds1106703010.22034/kjm.2018.67030ENİrem KüpeliErkenFaculty of Engineering and Natural Sciences, Department of Mathematics,
Bursa Technical University, Bursa, Turkey.Journal Article20180118The object of the present paper is to study almost $\alpha $-cosymplectic manifolds. We consider projectively flat, conformally flat, and concircularly flat almost $\alpha $-cosymplectic manifolds (with the $\eta $-parallel tensor field $\phi h$) and get some new properties. We conclude the paper by giving an example of $\alpha $-Kenmotsu manifold, which verifies our results.https://www.kjm-math.org/article_67030_b36cd9107ed71f514da1f1c232d7e881.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47885120190101Exponential Stability Analysis for Delay-Differential Systems of Neutral Type with an LMI Approach11207349910.22034/kjm.2018.73499ENVeerakyathaiahUmeshaDepartment of Mathematics, Dayananda sagar college of Engineering, Kumaraswamy layout, Bangalore, Karnataka, India.SpirangaiahPadmanabhanDepartment of Mathematics, R N S I T, Uttarahalli-Kengeri Road, Bangalore, Karnataka, India.0000-0002-1786-5831P.BaskarDepartment of Mathematics, New Horizon college of Engineering, Bangalore, Karnataka, India.MuhammadSyed AliDepartment of Pure Mathematics, Thiruvalluvar University, Vellore 632-
115, Tamilnadu, India.Journal Article20180531In this paper for neutral delay differential systems, the problem of determining the exponential stability is investigated. Based on the Lyapunov method, we present some useful criteria of exponential stability for the derived systems. The stability criterion is formulated in terms of linear matrix inequality (LMI),which can be easily solved by using the MATLAB LMI toolbox. Numerical examples are included to illustrate the proposed method.https://www.kjm-math.org/article_73499_aafcf9d48fb015be832da281da3efe11.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47885120190101The Approximate Solutions of Fractional Integro-Differential Equations by Using Modified Adomian Decomposition Method21397359310.22034/kjm.2018.73593ENAhmed AbdullahHamoudDepartment of Mathematics Faculty of Education and Science, Taiz University, Taiz, Yemen.0000-0002-8877-7337KirtiwantGhadleDepartment of Mathematics, Dr. Babasaheb Ambedkar Marathwada University,
Aurangabad 431-004, India.0000-0003-3205-5498ShakirAtshanDepartment of Mathematics, Thi Qar Directorates of Education, Ministry of Education, Iraq.Journal Article20180626The main object of the present paper is to study the behavior of the approximated solutions of the Caputo fractional Volterra-Fredholm integro-differential equations by using modified Adomian decomposition method. Moreover, we discuss some new existence, uniqueness, and convergence results. Finally, an example is included to demonstrate the validity and applicability of the proposed technique.https://www.kjm-math.org/article_73593_6dc1e8da8bef248712e90632993e6c0c.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47885120190101Dynamic Response of an Elastically Connected Double Non-Mindlin Plates with Simply-Supported End Condition due to Moving Load40597385410.22034/kjm.2018.73854ENJacob AbiodunGbadeyanDepartment of Mathematics, University of Ilorin, Ilorin, Kwara-State, Nigeria.Oluwatayo MichaelOgunmiloroDepartment of Mathematics, Ekiti - State University(EKSU), Ado-Ekiti, Ekiti - State, Nigeria.0000-0002-0800-3690Sunday EmmanuelFadugbaDepartment of Mathematics, Ekiti - State University(EKSU), Ado-Ekiti, Ekiti - State, Nigeria.Journal Article20180531In this paper, the dynamic response of two identical parallel non-mindlin (i.e., not taking into account the effect of shear deformation and rotatory inertia) plates which are elastically connected and subjected to a constant moving load is considered. The fourth order coupled partial differential governing equations is formulated and solved, using an approximate analytical method by assuming; firstly, a series solution later on treating the resulting coupled second order ordinary differential equations with an asymptotic method of Struble. The differential transform method, being a semi-analytical technique, is applied to the reduced coupled second order ordinary differential equations, to get a non-oscillatory series solution. An after treatment technique, comprising of the Laplace transform and Pade approximation techniques, is finally used via MAPLE ODE solver to make the series solution oscillatory. The dynamic deflections of the upper and lower plates are presented in analytical closed forms. The effect of the moving speed of the load and the elasticity of the elastic layer on the dynamic responses of the double plate systems is graphically shown and studied in details. The graphs of the plate's deflections for different speed parameters were plotted. It is however observed that the transverse deflections of each of the plates increase with an increase in different values of velocities for the moving load for a fixed time $t$.https://www.kjm-math.org/article_73854_83d31b7b005db96ff9db98c737010e46.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47885120190101On T-Extensions of Abelian Groups60687422010.22034/kjm.2018.74220ENAliakbarAlijaniMollasadra Technical and Vocational College, Technical and Vocational University, Ramsar, Iran.HosseinSahlehDepartment of Mathematics, University of Guilan, P. O. Box 1914, Rasht, Iran.Journal Article20180612Let $\Re$ be the category of all discrete abelian groups, and let $\cal{L}$ be the category of all locally compact abelian (LCA) groups. For a group $G\in \cal{L}$, the maximal torsion subgroup of $G$ is denoted by $tG$. A short exact sequence $0\to A\stackrel{\phi}{\to} B\stackrel{\psi}{\to}C\to 0$ in $\Re$ is said to be a t-extension if $0\to tA\stackrel{\phi}{\to} tB\stackrel{\psi}{\to}tC\to 0$ is a short exact sequence. We show that the set of all t-extensions of $A$ by $C$ is a subgroup of $Ext(C,A)$, which contains $Pext(C,A)$ for discrete abelian groups $A$ and $C$. We establish conditions under which the t-extensions split and determine those groups in $\Re$ which are t-injective or t-projective in $\Re$. Finally we determine the compact groups $G$ in $\cal{L}$ such that every pure extension of $G$ by a compact connected group $C\in \cal{L}$ splits.https://www.kjm-math.org/article_74220_a9f5d5879c28658ed606d177fed55aa0.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47885120190101On Randers Change of Generalized $m$th Root Metric69787527810.22034/kjm.2018.75278ENManojKumarDST-Centre for Interdisciplinary Mathematical Sciences, Institute of Science, Banaras Hindu University, Varanasi-221005, India.Journal Article20180719In the present paper, we find a condition under which a Finsler space with Randers change of generalized $m$th root metric is projectively related to an $m$th root metric. Then we find a condition under which Randers change of generalized $m$th root Finsler metric is locally projectively flat and also find a condition for locally dually flatness.https://www.kjm-math.org/article_75278_d06809e915d950b5df2806938c6d5b6f.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47885120190101Ruscheweyh-Type Harmonic Functions Defined By $q$- Differential Operators79888121210.22034/kjm.2019.81212ENGangadharanMurugusundaramoorthyDepartment of Mathematics, School of Advanced Sciences, Vellore Institute of Technology, Vellore - 632014, India.0000-0001-8285-6619Jay M.JahangiriMathematical Sciences, Kent State University, Kent, Ohio, U.S.A.Journal Article20180721A class of Ruscheweyh-type harmonic functions is defined, using $q$-differential operators and sufficient coefficient conditions for this class is determined. We then consider a subclass of the aforementioned class consisting of functions with real coefficients and obtain necessary and sufficient coefficient bounds, distortion theorem, extreme points, and convex combination conditions for such class. It is shown that the classes of functions considered in this paper contain various well-known as well as new classes of harmonic functions.https://www.kjm-math.org/article_81212_6cf18940b12156412dcfac780d5c4d20.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47885120190101Almost conformal Ricci solitons on $f$-Kenmotsu Manifolds891048122110.22034/kjm.2019.81221ENShyamal KumarHuiDepartment of Mathematics, The University of Burdwan, Golapbag, Burdwan – 713104, West Bengal, India.Sunil KumarYadavDepartment of Mathematics, Poornima College of Engineering, ISI-6, RIICO
Institutional Area, Sitapura, Jaipur – 302022, Rajasthan, India.AkshoyPatraDepartment of Mathematics, Govt. College of Engineering and Technology, Berhampur, Murshidabad – 742101, West Bengal, India.Journal Article20180504The object of the present paper is to study the $\phi $-Ricci symmetric, locally $\phi $-Ricci symmetric and cyclic Ricci parallel three-dimensional $f$-Kenmotsu manifold bearing the function $f$ being constant. We have considered almost conformal Ricci soliton on the three-dimensional $f$-Kenmostu manifold and deduced the condition for an almost conformal Ricci soliton, which becomes conformal Ricci soliton. Finally, examples on three-dimensional $f$-Kenmotsu manifold depending on nature of $f$ are constructed to illustrate the results.https://www.kjm-math.org/article_81221_ef73fb5317c2abd196bf85fc43cda852.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47885120190101On The Stability of The Quasi-Linear Implicit Equations in Hilbert Spaces1051128122210.22034/kjm.2019.81222ENMehdiBenabdallahDepartment of Mathematics, Faculty of Math and Computer, USTOran,
31000, AlgeriaMohamedHaririDepartment of Mathematics, University of Djillali Liabes, Sidi Bel-Abbes,
22000, Algeria.Journal Article20180501We use the generalized theorem of Liapounov to obtain some necessary and sufficient conditions for the stability of the stationary implicit equation $$Ax'(t)=Bx(t) ,\quad t\geq 0 ,$$ where $A$ and $B$ are bounded operators in Hilbert spaces. The achieved results can be applied to the stability for the quasi-linear implicit equation $$Ax'(t)=Bx(t)+\theta(t,x(t)),\quad t\geq 0 .$$https://www.kjm-math.org/article_81222_42e39894a1979bb86b55e195a4835a6e.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47885120190101On Approximation by $(p,q)$-Meyer-König-Zeller Durrmeyer Operators1131248122310.22034/kjm.2019.81223ENHoneySharmaDepartment of Mathematics, Gulzar Group of Institutes, Punjab, India.0000-0002-0904-2245CheenaGuptaI K G Punjab Technical University, Punjab, India.RamapatiMauryaI K G Punjab Technical University, Punjab, India;
Department of Mathematics, Manav Rachna University, Haryana, India.Journal Article20180504In this paper, we introduce a Durrmeyer type modification of Meyer-König-Zeller operators based on $(p,q)$-integers. The rate of convergence of these operators is explored with the help of Korovkin type theorems. We establish some direct results for proposed operators. We also obtain statistical approximation properties of operators. In the last section, we show the rate of convergence of $(p,q)$-Meyer-König-Zeller Durrmeyer operators for some functions by means of MATLAB programming.https://www.kjm-math.org/article_81223_7fe57d6463c07a48bf3f40586cfbc49b.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47885120190101On Two Generation Methods for The Simple Linear Group $PSL(3,5)$1251398122610.22034/kjm.2019.81226ENAyoub Basheer MohammedBasheerSchool of Mathematical and Computer Sciences, University of Limpopo
(Turfloop), P Bag X1106, Sovenga 0727, South AfricaThekiso TrevorSeretloSchool of Mathematical and Computer Sciences, University of Limpopo
(Turfloop), P Bag X1106, Sovenga 0727, South AfricaJournal Article20180731A finite group $G$ is said to be $(l,m, n)$-generated, if it is a quotient group of the triangle group $T(l,m, n) = \left<x,y, z|x^{l} = y^{m} = z^{n} = xyz = 1\right>.$ In [Nova J. Algebra and Geometry, 2 (1993), no. 3, 277--285], Moori posed the question of finding all the $(p,q,r)$ triples, where $p,\ q,$ and $r$ are prime numbers, such that a nonabelian finite simple group $G$ is $(p,q,r)$-generated. Also for a finite simple group $G$ and a conjugacy class $X$ of $G,$ the rank of $X$ in $G$ is defined to be the minimal number of elements of $X$ generating $G.$ In this paper, we investigate these two generational problems for the group $PSL(3,5),$ where we will determine the $(p,q,r)$-generations and the ranks of the classes of $PSL(3,5).$ We approach these kind of generations using the structure constant method. GAP [The GAP Group, GAP-Groups, Algorithms, and Programming, Version 4.9.3; 2018. (http://www.gap-system.org)] is used in our computations.https://www.kjm-math.org/article_81226_0b11fe80a831ac221e4f219d8e01381f.pdfDepartment of Pure Mathematics, Ferdowsi University of Mashhad (in cooperation with the Center of Excellence in Analysis on Algebraic Structures)Khayyam Journal of Mathematics2423-47885120190101Coefficients of Bi-Univalent Functions Involving Pseudo-Starlikeness Associated with Chebyshev Polynomials1401498123110.22034/kjm.2019.81231ENIbrahimAwolereDepartment of Mathematics, Emmanuel Alayande College of Education, P.
M. B. 1010, Oyo, Oyo State, Nigeria.Abiodun TinuoyeOladipoDepartment of Pure and Applied Mathematics, Ladoke Akintola University
of Tecchnology, Ogbomoso, Oyo State, Nigeria.Journal Article20180611In the present paper, a new subclass of analytic and bi-univalent functions by means of pseudo starlike function, activation function and Chebyshev polynomials are introduced. Coefficient bounds for functions belonging to the said subclass are obtained. Relevance connection of our class to second Hankel determinants is established.https://www.kjm-math.org/article_81231_3bd1e952383059c6791a5d546ecb0d03.pdf