ORIGINAL_ARTICLE
Stability Results for Neutral Integro-Differential Equations with Multiple Functional Delays
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.
http://www.kjm-math.org/article_43831_2161050be631ca19a702fe6a0bd6d1c3.pdf
2017-01-01T11:23:20
2021-01-23T11:23:20
1
11
10.22034/kjm.2017.43831
Stability
integro-differential equation
functional delay
Ernest
Yankson
ernestoyank@gmail.com
true
1
Department of Mathematics and Statistics, University of Cape Coast, Cape Coast, Ghana.
Department of Mathematics and Statistics, University of Cape Coast, Cape Coast, Ghana.
Department of Mathematics and Statistics, University of Cape Coast, Cape Coast, Ghana.
LEAD_AUTHOR
ORIGINAL_ARTICLE
Periodic Solutions for Third-Order Nonlinear Delay Differential Equations with Variable Coefficients
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.
http://www.kjm-math.org/article_44493_fca28ec0388a064bcfebffd47c16b12f.pdf
2017-01-01T11:23:20
2021-01-23T11:23:20
12
21
10.22034/kjm.2017.44493
fixed point
periodic solutions
third-order nonlinear delay differential equations
Abdelouaheb
Ardjouni
abd_ardjouni@yahoo.fr
true
1
Department of Mathematics and Informatics, University of Souk Ahras, P.O. Box 1553, Souk Ahras, 41000, Algeria.
Department of Mathematics and Informatics, University of Souk Ahras, P.O. Box 1553, Souk Ahras, 41000, Algeria.
Department of Mathematics and Informatics, University of Souk Ahras, P.O. Box 1553, Souk Ahras, 41000, Algeria.
LEAD_AUTHOR
Farid
Nouioua
fnouioua@gmail.com
true
2
Department of Mathematics and Informatics, University of Souk Ahras, P.O. Box 1553, Souk Ahras, 41000, Algeria.
Department of Mathematics and Informatics, University of Souk Ahras, P.O. Box 1553, Souk Ahras, 41000, Algeria.
Department of Mathematics and Informatics, University of Souk Ahras, P.O. Box 1553, Souk Ahras, 41000, Algeria.
AUTHOR
Ahcene
Djoudi
adjoudi@yahoo.com
true
3
Department of Mathematics, University of Annaba, P.O. Box 12, Annaba, 23000, Algeria.
Department of Mathematics, University of Annaba, P.O. Box 12, Annaba, 23000, Algeria.
Department of Mathematics, University of Annaba, P.O. Box 12, Annaba, 23000, Algeria.
AUTHOR
ORIGINAL_ARTICLE
Operators Reversing Orthogonality and Characterization of Inner Product Spaces
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.
http://www.kjm-math.org/article_44746_9f829bbb7fc2df9483fd2622f9084732.pdf
2017-01-01T11:23:20
2021-01-23T11:23:20
22
24
10.22034/kjm.2017.44746
Birkhoff orthogonality
orthogonality reversing mappings
characterizations of inner product spaces
Paweł
Wójcik
pwojcik@up.krakow.pl
true
1
Institute of Mathematics, Pedagogical University of Cracow, Podchorążych 2, 30-084 Kraków, Poland.
Institute of Mathematics, Pedagogical University of Cracow, Podchorążych 2, 30-084 Kraków, Poland.
Institute of Mathematics, Pedagogical University of Cracow, Podchorążych 2, 30-084 Kraków, Poland.
LEAD_AUTHOR
ORIGINAL_ARTICLE
Certain Properties of a Subclass of Univalent Functions With Finitely Many Fixed Coefficients
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.
http://www.kjm-math.org/article_44920_245bef22255f8b0b38f19d4c0c83a25b.pdf
2017-01-01T11:23:20
2021-01-23T11:23:20
25
32
10.22034/kjm.2017.44920
Analytic function
univalent function
fixed coefficient
Extreme point
S.Sunil
Varma
sunilvarma@mcc.edu.in
true
1
Department of Mathematics, Madras Christian College, Tambaram, Chennai-600059, Tamil Nadu, India
Department of Mathematics, Madras Christian College, Tambaram, Chennai-600059, Tamil Nadu, India
Department of Mathematics, Madras Christian College, Tambaram, Chennai-600059, Tamil Nadu, India
LEAD_AUTHOR
Thomas
Rosy
thomas.rosy@gmail.com
true
2
Department of Mathematics, Madras Christian College, Tambaram, Chennai-600059, Tamil Nadu, India
Department of Mathematics, Madras Christian College, Tambaram, Chennai-600059, Tamil Nadu, India
Department of Mathematics, Madras Christian College, Tambaram, Chennai-600059, Tamil Nadu, India
AUTHOR
ORIGINAL_ARTICLE
On Para-Sasakian Manifolds Satisfying Certain Curvature Conditions with Canonical Paracontact Connection
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.
http://www.kjm-math.org/article_45190_7d44a17d67db3000195bfd95cc73a650.pdf
2017-01-01T11:23:20
2021-01-23T11:23:20
33
43
10.22034/kjm.2017.45190
Canonical connection
paracontact metric structure
normal structure
Selcen
Yüksel Perktaş
sperktas@adiyaman.edu.tr
true
1
Faculty of Arts and Science, Department of Mathematics, Adıyaman University, Adıyaman, Turkey
Faculty of Arts and Science, Department of Mathematics, Adıyaman University, Adıyaman, Turkey
Faculty of Arts and Science, Department of Mathematics, Adıyaman University, Adıyaman, Turkey
LEAD_AUTHOR
ORIGINAL_ARTICLE
Approximation for a Summation-Integral Type Link Operators
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.
http://www.kjm-math.org/article_45322_725917aec0e6b1c459fe81fc2e4d7411.pdf
2017-01-01T11:23:20
2021-01-23T11:23:20
44
60
10.22034/kjm.2017.45322
Global approximation
Rate of convergence
Modulus of continuity
bounded variation
Arun
Kajla
rachitkajla47@gmail.com
true
1
Department of Mathematics, Central University of Haryana, Haryana-123031, India.
Department of Mathematics, Central University of Haryana, Haryana-123031, India.
Department of Mathematics, Central University of Haryana, Haryana-123031, India.
LEAD_AUTHOR
ORIGINAL_ARTICLE
Ostrowski's Inequality for Functions whose First Derivatives are $s$-Preinvex in the Second Sense
In this paper, we establish some new Ostrowski type inequalities forfunctions whose first derivatives are $s$-preinvex in the second sense.
http://www.kjm-math.org/article_46863_69c7dd0b531fa53298dd16c90cd3a0f8.pdf
2017-01-01T11:23:20
2021-01-23T11:23:20
61
80
10.22034/kjm.2017.46863
Ostrowski inequality
midpoint inequality
H"{o}lder inequality
power mean inequality
preinvex functions
$s$-preinvex functions
Badreddine
Meftah
badrimeftah@yahoo.fr
true
1
Laboratoire des t'el'ecommunications, Facult'e des Sciences et de la Technologie, University of 8 May 1945 Guelma, P.O. Box 401, 24000 Guelma, Algeria.
Laboratoire des t'el'ecommunications, Facult'e des Sciences et de la Technologie, University of 8 May 1945 Guelma, P.O. Box 401, 24000 Guelma, Algeria.
Laboratoire des t'el'ecommunications, Facult'e des Sciences et de la Technologie, University of 8 May 1945 Guelma, P.O. Box 401, 24000 Guelma, Algeria.
LEAD_AUTHOR
ORIGINAL_ARTICLE
Proximal Point Algorithms for Numerical Reckoning Fixed Points of Hybrid-Type Multivalued Mappings in Hilbert Spaces
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.
http://www.kjm-math.org/article_46951_9c228d2ed70ca44facd3ac48e7b8797e.pdf
2017-01-01T11:23:20
2021-01-23T11:23:20
81
89
10.22034/kjm.2017.46951
Proximal point algorithm
hybrid multivalued mapping
Ishikawa iteration
S-iteration
Hilbert spaces
Kritsada
Lerkchaiyaphum
a_krit2@hotmail.com
true
1
Department of Mathematics, Faculty of Science and Technology, Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand.
Department of Mathematics, Faculty of Science and Technology, Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand.
Department of Mathematics, Faculty of Science and Technology, Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand.
AUTHOR
Withun
Phuengrattana
withun_ph@yahoo.com
true
2
Research Center for Pure and Applied Mathematics, Research and Development Institute, Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand.
Research Center for Pure and Applied Mathematics, Research and Development Institute, Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand.
Research Center for Pure and Applied Mathematics, Research and Development Institute, Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand.
LEAD_AUTHOR