2021-04-13T11:40:25Z
http://www.kjm-math.org/?_action=export&rf=summon&issue=8601
Khayyam Journal of Mathematics
Khayyam J. Math.
2019
5
1
On a Classification of Almost $alpha $-Cosymplectic Manifolds
İrem
Erken
The 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.
Almost α-Cosymplectic manifold
projectively flat
conformally flat
concircularly flat
2019
01
01
1
10
http://www.kjm-math.org/article_67030_b36cd9107ed71f514da1f1c232d7e881.pdf
Khayyam Journal of Mathematics
Khayyam J. Math.
2019
5
1
Exponential Stability Analysis for Delay-Differential Systems of Neutral Type with an LMI Approach
Veerakyathaiah
Umesha
Spirangaiah
Padmanabhan
P.
Baskar
Muhammad
Syed Ali
In 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.
Neutral system
exponential stability
Lyapunov method
linear matrix inequality (LMI)
2019
01
01
11
20
http://www.kjm-math.org/article_73499_aafcf9d48fb015be832da281da3efe11.pdf
Khayyam Journal of Mathematics
Khayyam J. Math.
2019
5
1
The Approximate Solutions of Fractional Integro-Differential Equations by Using Modified Adomian Decomposition Method
Ahmed
Hamoud
Kirtiwant
Ghadle
Shakir
Atshan
The 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.
Modified Adomian decomposition method
Caputo fractional derivative
fractional Volterra--Fredholm integro-differential equation
approximate solution
2019
01
01
21
39
http://www.kjm-math.org/article_73593_6dc1e8da8bef248712e90632993e6c0c.pdf
Khayyam Journal of Mathematics
Khayyam J. Math.
2019
5
1
Dynamic Response of an Elastically Connected Double Non-Mindlin Plates with Simply-Supported End Condition due to Moving Load
Jacob
Gbadeyan
Oluwatayo
Ogunmiloro
Sunday
Fadugba
In 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 $t$.
Moving load
non-mindlin
simply-supported
Struble's method
2019
01
01
40
59
http://www.kjm-math.org/article_73854_83d31b7b005db96ff9db98c737010e46.pdf
Khayyam Journal of Mathematics
Khayyam J. Math.
2019
5
1
On T-Extensions of Abelian Groups
Aliakbar
Alijani
Hossein
Sahleh
Let $\Re$ 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.
T-extensions
extensions
pure extensions
locally compact abelian groups
2019
01
01
60
68
http://www.kjm-math.org/article_74220_a9f5d5879c28658ed606d177fed55aa0.pdf
Khayyam Journal of Mathematics
Khayyam J. Math.
2019
5
1
On Randers Change of Generalized $m$th Root Metric
Manoj
Kumar
In 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.
Finsler space
Randers change of generalized $m$th root metrics
projectively related metrics
locally projectively flat metric
locally dually flat metric
2019
01
01
69
78
http://www.kjm-math.org/article_75278_d06809e915d950b5df2806938c6d5b6f.pdf
Khayyam Journal of Mathematics
Khayyam J. Math.
2019
5
1
Ruscheweyh-Type Harmonic Functions Defined By $q$- Differential Operators
Gangadharan
Murugusundaramoorthy
Jay
Jahangiri
A 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.
Univalent
harmonic starlike
$q$- differential operators
2019
01
01
79
88
http://www.kjm-math.org/article_81212_6cf18940b12156412dcfac780d5c4d20.pdf
Khayyam Journal of Mathematics
Khayyam J. Math.
2019
5
1
Almost conformal Ricci solitons on $f$-Kenmotsu Manifolds
Shyamal
Hui
Sunil
Yadav
Akshoy
Patra
The 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.
$f$-Kenmotsu manifold
almost conformal Ricci soliton
$phi $-symmetric
cyclic Ricci parallel
torqued vector field
2019
01
01
89
104
http://www.kjm-math.org/article_81221_ef73fb5317c2abd196bf85fc43cda852.pdf
Khayyam Journal of Mathematics
Khayyam J. Math.
2019
5
1
On The Stability of The Quasi-Linear Implicit Equations in Hilbert Spaces
Mehdi
Benabdallah
Mohamed
Hariri
We 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 $$Ax'(t)=Bx(t)+\theta(t,x(t)),\quad t\geq 0 .$$
exponential stability
operator theory
implicit equations
2019
01
01
105
112
http://www.kjm-math.org/article_81222_42e39894a1979bb86b55e195a4835a6e.pdf
Khayyam Journal of Mathematics
Khayyam J. Math.
2019
5
1
On Approximation by $(p,q)$-Meyer-König-Zeller Durrmeyer Operators
Honey
Sharma
Cheena
Gupta
Ramapati
Maurya
In 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.
$(p, q)$-Calculus, $(p, q)$-Meyer-König-Zeller operator
Modulus of continuity
Peetre $K$-functional
statistical convergence
2019
01
01
113
124
http://www.kjm-math.org/article_81223_7fe57d6463c07a48bf3f40586cfbc49b.pdf
Khayyam Journal of Mathematics
Khayyam J. Math.
2019
5
1
On Two Generation Methods for The Simple Linear Group $PSL(3,5)$
Ayoub
Basheer
Thekiso
Seretlo
A 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.
Conjugacy classes
$(p, q, r)$-generation
rank
structure constant
2019
01
01
125
139
http://www.kjm-math.org/article_81226_0b11fe80a831ac221e4f219d8e01381f.pdf
Khayyam Journal of Mathematics
Khayyam J. Math.
2019
5
1
Coefficients of Bi-Univalent Functions Involving Pseudo-Starlikeness Associated with Chebyshev Polynomials
Ibrahim
Awolere
Abiodun
Oladipo
In 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.
univalent functions
Chebyshev polynomials
pseudo starlike function
Hankel determinant
2019
01
01
140
149
http://www.kjm-math.org/article_81231_3bd1e952383059c6791a5d546ecb0d03.pdf