Browsing by Author "Tas, Kenan"

Now showing 1 - 20 of 52

Citation - WoS: 79
Citation - Scopus: 82
A generalized contraction principle with control functions on partial metric spaces
(Pergamon-elsevier Science Ltd, 2012) Abdeljawad, Thabet; Karapinar, Erdal; Tas, Kenan; 19184; 4971; Matematik
Partial metric spaces were introduced by Matthews in 1994 as a part of the study of denotational semantics of data flow networks. In this article, we prove a generalized contraction principle with control functions phi and psi on partial metric spaces. The theorems we prove generalize many previously obtained results. We also give some examples showing that our theorems are indeed proper extensions. (C) 2011 Elsevier Ltd. All rights reserved.
Citation - WoS: 8
Citation - Scopus: 8
A new method for dissipative dynamic operator with transmission conditions
(Springer Basel Ag, 2018) Ugurlu, Ekin; Tas, Kenan; 238990; 4971; Matematik
In this paper, we investigate the spectral properties of a boundary value transmission problem generated by a dynamic equation on the union of two time scales. For such an analysis we assign a suitable dynamic operator which is in limit-circle case at infinity. We also show that this operator is a simple maximal dissipative operator. Constructing the inverse operator we obtain some information about the spectrum of the dissipative operator. Moreover, using the Cayley transform of the dissipative operator we pass to the contractive operator which is of the class With the aid of the minimal function we obtain more information on the dissipative operator. Finally, we investigate other properties of the contraction such that multiplicity of the contraction, unitary colligation with basic operator and CMV matrix representation associated with the contraction.
Citation - WoS: 3
A new transform method in nabla discrete fractional calculus
(Springer, 2012) Jarad, Fahd; Kaymakcalan, Billur; Tas, Kenan; 4971; Matematik
Starting from the definition of the Sumudu transform on a general nabla time scale, we define the generalized nabla discrete Sumudu transform. We obtain the nabla discrete Sumudu transform of Taylor monomials, fractional sums, and differences. We apply this transform to solve some fractional difference equations with initial value problems. MSC: 44A15, 44A55.
Citation - WoS: 7
Citation - Scopus: 9
A unique common triple fixed point theorem for hybrid pair of maps
(Hindawi Publishing Corp, 2012) Rao, K. P. R.; Kishore, G. N. V.; Tas, Kenan; 4971; Matematik
We obtain a unique common triple fixed point theorem for hybrid pair of mappings in metric spaces. Our result extends the recent results of B. Samet and C. Vetro (2011). We also introduced a suitable example supporting our result.
Citation - WoS: 2
Citation - Scopus: 0
A Unique Coupled Common Fixed Point Theorem for Symmetric (P,P) -Contractive Mappings in Ordered G -Metric Spaces With Applications
(Hindawi Ltd, 2013) Jain, Manish; Tas, Kenan; 4971; Matematik
We establish the existence and uniqueness of coupled common fixed point for symmetric (phi, psi)-contractive mappings in the framework of ordered G-metric spaces. Present work extends, generalize, and enrich the recent results of Choudhury and Maity (2011), Nashine (2012), and Mohiuddine and Alotaibi (2012), thereby, weakening the involved contractive conditions. Our theoretical results are accompanied by suitable examples and an application to integral equations.
Citation - WoS: 4
Advances on Fixed Point Results on Partial Metric Spaces
(Springer international Publishing Ag, 2019) Karapinar, Erdal; Tas, Kenan; Rakocevic, Vladimir; 1918; 4971; Matematik
Citation - WoS: 3
Citation - Scopus: 2
An original coupled coincidence point result for a pair of mappings without MMP
(Springeropen, 2014) Chandok, Sumit; Tas, Kenan; 4971; Matematik
The purpose of this paper is to establish a coupled coincidence point theorem for a pair of mappings without MMP (mixed monotone property) in metric spaces endowed with partial order, which is not an immediate consequence of a well-known theorem in the literature. Also, we present a result on the existence and uniqueness of coupled common fixed points. The results presented in the paper generalize and extend some of the results of Bhaskar and Lakshmikantham (Nonlinear Anal. 65: 1379-1393, 2006), Choudhury, Metiya and Kundu (Ann. Univ. Ferrara 57:1-16, 2011), Harjani, Lopez and Sadarangani (Nonlinear Anal. 74:1749-1760, 2011) and of Luong and Thuan (Bull. Math. Anal. Appl. 2:16-24, 2010) for the mappings having no MMP. We introduce an example that there exists a common coupled fixed point of the mappings g and F such that F does not satisfy the g-mixed monotone property, and also g and F do not commute.
Citation - WoS: 7
Citation - Scopus: 13
Approximate Controllability of Infinite-Dimensional Degenerate Fractional Order Systems in the Sectorial Case
(Mdpi, 2019) Baleanu, Dumitru; Fedorov, Vladimir E.; Gordievskikh, Dmitriy M.; Tas, Kenan; 4971; 56389; Matematik
We consider a class of linear inhomogeneous equations in a Banach space not solvable with respect to the fractional Caputo derivative. Such equations are called degenerate. We study the case of the existence of a resolving operators family for the respective homogeneous equation, which is an analytic in a sector. The existence of a unique solution of the Cauchy problem and of the Showalter-Sidorov problem to the inhomogeneous degenerate equation is proved. We also derive the form of the solution. The approximate controllability of infinite-dimensional control systems, described by the equations of the considered class, is researched. An approximate controllability criterion for the degenerate fractional order control system is obtained. The criterion is illustrated by the application to a system, which is described by an initial-boundary value problem for a partial differential equation, not solvable with respect to the time-fractional derivative. As a corollary of general results, an approximate controllability criterion is obtained for the degenerate fractional order control system with a finite-dimensional input.
Citation - WoS: 19
Citation - Scopus: 18
Best proximity point theorems for KT-types cyclic orbital contraction mappings
(House Book Science-casa Cartii Stiinta, 2012) Karapinar, Erdal; Petrusel, Gabriela; Tas, Kenan; 19184; 4971; Matematik
In this manuscript, three new KT-types cyclic orbital contractions are defined and some related best proximity point theorems are given. Also, the notion of KT-type cyclic orbital Meir-Keeler contraction is defined and some fixed point theorems for this class of mappings are proved. The results of this manuscript generalize some theorems, on the same subject, of several authors, such as Kirk-Srinavasan-Veeramani, Eldered-Veeramani and Karpagam-Agrawal.
Citation - WoS: 7
Citation - Scopus: 8
Common fixed point theorems for generalized (phi,psi)-weak contraction condition in complete metric spaces
(Springer international Publishing Ag, 2015) Murthy, Penumarthy Parvateesam; Tas, Kenan; Patel, Uma Devi; 4971; Matematik
The intent of this manuscript is to establish some common fixed point theorems in a complete metric space under weak contraction condition for two pairs of discontinuous weak compatible maps. The results proved herein are the generalization of some recent results in literature. We give an example to support our results.
Citation - WoS: 16
Citation - Scopus: 20
Common fixed point theorems in cone banach spaces
(Hacettepe Univ, Fac Sci, 2011) Abdeljawad, Thabet; Tas, Kenan; Karapınar, Erdal; 19184; 4971; Matematik
Recently, E. Karapınar (Fixed Point Theorems in Cone Banach Spaces, Fixed Point Theory Applications, Article ID 609281, 9 pages, 2009) presented some fixed point theorems for self-mappings satisfying certain contraction principles on a cone Banach space. Here we will give some generalizations of this theorem.
Citation - WoS: 1
Citation - Scopus: 3
Common fixed point theorems in modified ıntuitionistic fuzzy metric spaces
(Hindawi Ltd, 2013) Manro, Saurabh; Kumar, Sanjay; Bhatia, S. S.; Tas, Kenan; 4971; Matematik
This paper consists of main two sections. In the first section, we prove a common fixed point theorem in modified intuitionistic fuzzy metric space by combining the ideas of pointwise R-weak commutativity and reciprocal continuity of mappings satisfying contractive conditions. In the second section, we prove common fixed point theorems in modified intuitionistic fuzzy metric space from the class of compatible continuous mappings to noncompatible and discontinuous mappings. Lastly, as an application, we prove fixed point theorems using weakly reciprocally continuous noncompatible self-mappings on modified intuitionistic fuzzy metric space satisfying some implicit relations.
Citation - WoS: 13
Citation - Scopus: 0
Common Fixed Point Theorems in Modified Intuitionistic Fuzzy Metric Spaces (Vol 2013, 189321, 2013)
(Hindawi Publishing Corporation, 2014) Manro, Saurabh; Kumar, Sanjay; Bhatia, S. S.; Tas, Kenan
Citation - WoS: 10
Citation - Scopus: 16
Common fixed points of self maps satisfying an integral type contractive condition in fuzzy metric spaces
(Univ Osijek, dept Mathematics, 2010) Murthy, Penumarthy Parvateesam; Kumar, Sanjay; Tas, Kenan; 4971; Matematik
In this paper, first we prove fixed point theorems for different variant of compatible maps, satisfying a contractive condition of integral type in fuzzy metric spaces, which improve the results of Branciari [2], Rhoades [33], Kumar et al .[23], Subramanyam [35] and results of various authors cited in the literature of "Fixed Point Theory and Applications". Secondly, we introduce the notion of any kind of weakly compatible maps and prove a fixed point theorem for weakly compatible maps along with the notion of any kind of weakly compatible. At the end, we prove a fixed point theorem using variants of R-Weakly commuting mappings in fuzzy metric spaces.
Citation - WoS: 0
Citation - Scopus: 0
Commutative convolution of functions and distributions
(Taylor & Francis Ltd, 2007) Fisher, Brian; Tas, Kenan; 4971; Matematik
The commutative convolution f * g of two distributions f and g in D' is defined as the limit of the sequence {(f tau(n)) * (g tau(n))}, provided the limit exists, where {tau(n)} is a certain sequence of functions tn in D converging to 1. It is proved that |x|(lambda) * (sgn x|x|(-lambda-1)) = pi[cot (pi lambda) - cosec(pi lambda)] sgn x|x|(0), for lambda not equal 0, +/- 1, +/- 2, ... , where B denotes the Beta function.
Citation - WoS: 2
Citation - Scopus: 1
Coupled common fixed point results involving (Φ,Ψ)-contractions in ordered generalized metric spaces with application to integral equations
(Springeropen, 2013) Jain, Manish; Tas, Kenan; Gupta, Neetu; 4971; Matematik
We establish some coupled coincidence and coupled common fixed point theorems for the mixed g-monotone mappings satisfying -contractive conditions in the setting of ordered generalized metric spaces. Presented theorems extend and generalize the very recent results of Choudhury and Maity (Math. Comput. Model. 54(1-2):73-79, 2011). To illustrate our results, an example and an application to integral equations have also been given. MSC: 54H10, 54H25.
Citation - WoS: 16
Citation - Scopus: 6
Coupled common fixed point results involving a (phi,psi)-contractive condition for mixed g-monotone operators in partially ordered metric spaces
(Springeropen, 2012) Jain, Manish; Tas, Kenan; Kumar, Sanjay; Gupta, Neetu; 4971; Matematik
In the setting of partially ordered metric spaces, using the notion of compatible mappings, we establish the existence and uniqueness of coupled common fixed points involving a (phi,psi)-contractive condition for mixed g-monotone operators. Our results extend and generalize the well- known results of Berinde (Nonlinear Anal. TMA 74: 7347-7355, 2011; Nonlinear Anal. TMA 75:3218-3228, 2012) and weaken the contractive conditions involved in the results of Alotaibi et al. (Fixed Point Theory Appl. 2011: 44, 2011), Bhaskar et al. (Nonlinear Anal. TMA 65:1379-1393, 2006), and Luong et al. (Nonlinear Anal. TMA 74:983-992, 2011). The effectiveness of the presented work is validated with the help of suitable examples.
Citation - WoS: 31
Citation - Scopus: 27
Coupled fixed point theorems for a pair of weakly compatible maps along with CLRg property in fuzzy metric spaces
(Hindawi Publishing Corporation, 2012) Jain, Manish; Tas, Kenan; Kumar, Sanjay; Gupta, Neetu; 4971; Matematik
The aim of this paper is to extend the notions of E. A. property and CLRg property for coupled mappings and use these notions to generalize the recent results of Xin-Qi Hu (2011). The main result is supported by a suitable example.
Citation - WoS: 0
Citation - Scopus: 0
Coupled fixed points in complex partial metric spaces
(int Scientific Research Publications, 2022) Gunaseelan, M.; Khan, M. S.; Singh, Y. Mahendra; Tas, Kenan; 4971; Matematik
In this paper, we obtain coupled fixed point theorems in complex partial metric spaces under the different contractive conditions. Examples are provided to support our results.
Citation - WoS: 0
Citation - Scopus: 1
Dependence Of Eigenvalues Of Some Boundary Value Problems
(Tsing Hua Univ, dept Mathematics, 2021) Ugurlu, Ekin; Tas, Kenan; 4971; 238990; Matematik
In this work we deal with a system of two first-order differential equations containing the same eigenvalue parameter. We consider some suitable separated real and complex coupled boundary conditions, and show that the eigenvalues generated by this system are continuous in an eigenvalue branch. Also we introduce the ordinary and Frechet derivatives of these eigenvalues with respect to some elements of the data.