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Discrete Impulsive Sturm-Liouville Equation With Hyperboliceigenparameter, TURHAN KÖPRÜBAŞI, YELDA AYGAR KÜÇÜKEVCİLİOĞLU 2022 TÜBİTAK

Discrete Impulsive Sturm-Liouville Equation With Hyperboliceigenparameter, Turhan Köprübaşi, Yelda Aygar Küçükevci̇li̇oğlu

Turkish Journal of Mathematics

Let $L$ denote the selfadjoint difference operator of second order with boundary and impulsive conditions generated in $\ell _{2}\left( %TCIMACRO{\U{2115} } %BeginExpansion \mathbb{N} %EndExpansion \right) $ by \begin{equation*} a_{n-1}y_{n-1}+b_{n}y_{n}+a_{n}y_{n+1}=\left( 2\cosh z\right) y_{n}\text{ },% \text{ }n\in %TCIMACRO{\U{2115} } %BeginExpansion \mathbb{N} %EndExpansion \setminus \left\{ k-1,k,k+1\right\} , \end{equation*}% \begin{equation*} \begin{array}{c} y_{0}=0\text{ }, \\ \left\{ \begin{array}{c} y_{k+1}=\theta _{1}y_{k-1} \\ \bigtriangleup y_{k+1}=\theta _{2}\bigtriangledown y_{k-1} \end{array}% \right. ,\text{ }\theta _{1},\theta _{2}\in %TCIMACRO{\U{211d}}% %BeginExpansion \mathbb{R}, %EndExpansion \end{array}% \end{equation*} where $\left\{ a_{n}\right\} _{n\in %TCIMACRO{\U{2115} } %BeginExpansion \mathbb{N} %EndExpansion },$ $\left\{ b_{n}\right\} _{n\in %TCIMACRO{\U{2115} } %BeginExpansion \mathbb{N} %EndExpansion }$ are real sequences and $\bigtriangleup ,\bigtriangledown $ are respectively forward …


Limited Frequency Band Diffusive Representation For Nabla Fractional Order Transfer Functions, YIHENG WEI, YINGDONG WEI, YUQING HOU, XUAN ZHAO 2022 TÜBİTAK

Limited Frequency Band Diffusive Representation For Nabla Fractional Order Transfer Functions, Yiheng Wei, Yingdong Wei, Yuqing Hou, Xuan Zhao

Turkish Journal of Mathematics

Though infinite-dimensional characteristic is the natural property of nabla fractional order systems and it is the foundation of stability analysis, controller synthesis and numerical realization, there are few research focusing on this topic. Under this background, this paper concerns the diffusive representation of nabla fractional order systems. Firstly, several variants are developed for the elementary equality in frequency domain, i.e. $\frac{1}{s^\alpha} = \int_0^{ + \infty } {\frac{{{\mu _\alpha }( \omega )}}{{s + \omega }}{\rm{d}}\omega }$. Afterwards, the limited frequency band diffusive representation and the unit impulse response are derived for a series of nabla fractional order transfer functions. Finally, an …


Existence Of Solutions For An Infinite System Of Tempered Fractional Order Boundary Value Problems In The Spaces Of Tempered Sequences, KHUDDUSH MAHAMMAD, RAJENDRA PRASAD KAPULA, LEELA DODDI 2022 TÜBİTAK

Existence Of Solutions For An Infinite System Of Tempered Fractional Order Boundary Value Problems In The Spaces Of Tempered Sequences, Khuddush Mahammad, Rajendra Prasad Kapula, Leela Doddi

Turkish Journal of Mathematics

This paper deals with infinite system of nonlinear two-point tempered fractional order boundary value problems $$ \begin{aligned} {}^\mathtt{RL}_{~0}\mathbb{D}^{δ_2,\ell}_\mathtt{z}\Big[\mathtt{p}_\mathtt{j}(\mathtt{z})&{}^\mathtt{RL}_{~0}\mathbb{D}^{δ_1,\ell}_\mathtt{z} \vartheta_\mathtt{j}(\mathtt{z})\Big]=λ_\mathtt{j}\varphi\big(\mathtt{z},\vartheta(\mathtt{z})\big),\, \mathtt{z}\in[0,\mathtt{T}], δ_1,δ_2\in(1,2),\\ &\hskip0.25cm\vartheta_\mathtt{j}(0)=\lim_{\mathtt{z}\to0}\left[{}^\mathtt{RL}_{~0}\mathbb{D}^{δ_1,\ell}_\mathtt{z}(e^{\ell\mathtt{z}}\vartheta_\mathtt{j}(\mathtt{z}))\right]=0,\\ &e^{\ell\mathtt{T}}\vartheta_\mathtt{j}(\mathtt{T})=\lim_{\mathtt{z}\to\mathtt{T}}\left[{}^\mathtt{RL}_{~0}\mathbb{D}^{δ_1,\ell}_\mathtt{z}(e^{\ell\mathtt{z}}\vartheta_\mathtt{j}(\mathtt{z}))\right]=0, \end{aligned} $$ where $\mathtt{j}\in\{1,2,3,\cdot\cdot\cdot\},\,\ell\ge 0,$ ${}^\mathtt{RL}_{~0}\mathbb{D}^{\star,\ell}_\mathtt{z}$ denotes the Riemann--Liouville tempered fractional derivative of order $\star\in\{δ_1,δ_2\}$, $\vartheta(\mathtt{z})=\left(\vartheta_\mathtt{j}(\mathtt{z})\right)_{\mathtt{j}=1}^{\infty},$ $\varphi_\mathtt{j}:[0,\mathtt{T}]\to[0,\mathtt{T}]$ are continuous and we derive sufficient conditions for the existence of solutions to the system via the Hausdorff measure of noncompactness and Meir-Keeler fixed point theorem in tempered sequence spaces.


On Bounded Solutions Of A Second-Order Iterative Boundary Value Problem, SAFA CHOUAF, AHLEME BOUAKKAZ, RABAH KHEMIS 2022 TÜBİTAK

On Bounded Solutions Of A Second-Order Iterative Boundary Value Problem, Safa Chouaf, Ahleme Bouakkaz, Rabah Khemis

Turkish Journal of Mathematics

In this article, we investigate a second-order iterative differential equation with boundary conditions. The use of the principle of contraction mappings and the Schauder's fixed point theorem allows us to prove some existence and uniqueness results. Finally, an example is given to check the validity of our findings, which are new, and complete some published manuscripts to some degree.


Solvability Of Gripenberg's Equations Of Fractional Order With Perturbation Term In Weighted $L_P$-Spaces On ${\Mathbb{R}}^+$, MOHAMED M. A. METWALI 2022 TÜBİTAK

Solvability Of Gripenberg's Equations Of Fractional Order With Perturbation Term In Weighted $L_P$-Spaces On ${\Mathbb{R}}^+$, Mohamed M. A. Metwali

Turkish Journal of Mathematics

This article deals with the solvability of Gripenberg's equations of fractional order with a perturbation term in weighted Lebesgue spaces on ${\mathbb{R}}^+=[0,\infty)$ via the fixed point hypothesis and the measure of noncompactness. The uniqueness of the solutions for the studied problem is discussed. An example is included to validate our results. The results presented in the article extend and generalize some former results in the available literature.


Boundary Value Problems For A Second-Order $(P,Q) $-Difference Equation With Integral Conditions, İLKER GENÇTÜRK 2022 TÜBİTAK

Boundary Value Problems For A Second-Order $(P,Q) $-Difference Equation With Integral Conditions, İlker Gençtürk

Turkish Journal of Mathematics

Our purpose in this paper is to obtain some new existence results of solutions for a boundary value problem for a $ (p,q) $-difference equations with integral conditions, by using fixed point theorems. Examples illustrating the main results are also presented.


Solving Nonlinear Integro-Differential Equations Using Numerical Method, NEDJEM EDDINE RAMDANI, SANDRA PINELAS 2022 TÜBİTAK

Solving Nonlinear Integro-Differential Equations Using Numerical Method, Nedjem Eddine Ramdani, Sandra Pinelas

Turkish Journal of Mathematics

The aim of this paper is to establish conditions for the existence and uniqueness of the solution of a nonlinear integro-differential equation. Moreover, it is to propose a quadrature method in order to find an approximate solution and establish the convergence of the method. We conclude by providing the algorithm and some numerical simulation to confirm our theoretical results.


The Complex Error Functions And Various Extensive Results Together With Implications Pertaining To Certain Special Functions, HÜSEYİN IRMAK, PRAVEEN AGARWAL, RAVI P. AGARWAL 2022 TÜBİTAK

The Complex Error Functions And Various Extensive Results Together With Implications Pertaining To Certain Special Functions, Hüseyi̇n Irmak, Praveen Agarwal, Ravi P. Agarwal

Turkish Journal of Mathematics

The error functions play very important roles in science and technology. In this investigation, the error functions in the complex plane will be introduced, then comprehensive results together with several nonlinear implications in relation to the related complex functions will be indicated, and some possible special results of them will be next presented. Furthermore, various interesting or important suggestions will be also made for the scientific researchers who are interested in this topic.


A Discussion On The Existence And Uniqueness Analysis For The Coupled Two-Term Fractional Differential Equations, SACHIN KUMAR VERMA, RAMESH KUMAR VATS, AVADHESH KUMAR, VELUSAMY VIJAYAKUMAR, ANURAG SHUKLA 2022 TÜBİTAK

A Discussion On The Existence And Uniqueness Analysis For The Coupled Two-Term Fractional Differential Equations, Sachin Kumar Verma, Ramesh Kumar Vats, Avadhesh Kumar, Velusamy Vijayakumar, Anurag Shukla

Turkish Journal of Mathematics

This paper mainly concentrates on the study of a new boundary value problem of coupled nonlinear two-term fractional differential system. We make use of the theories on fractional calculus and fixed point approach to derive the existence and uniqueness results of the considered two-term fractional systems. To confirm the application of the stated outcomes, two examples are provided.


On Stability And Oscillation Of Fractional Differential Equations With A Distributed Delay, LIMEI FENG, SHURONG SUN 2022 TÜBİTAK

On Stability And Oscillation Of Fractional Differential Equations With A Distributed Delay, Limei Feng, Shurong Sun

Turkish Journal of Mathematics

In this paper, we study the stability and oscillation of fractional differential equations \begin{equation*} ^cD^\alpha x(t)+ax(t)+\int_0^1x(s+[t-1])dR(s)=0. \end{equation*} We discretize the fractional differential equation by variation of constant formula and semigroup property of Mittag-Leffler function, and get the difference equation corresponding to the integer points. From the equivalence analogy of qualitative properties between the difference equations and the original fractional differential equations, the necessary and sufficient conditions of oscillation, stability and exponential stability of the equations are obtained.


On The Existence For Parametric Boundary Value Problems Of A Coupled System Of Nonlinear Fractional Hybrid Differential Equations, YIGE ZHAO, YIBING SUN 2022 TÜBİTAK

On The Existence For Parametric Boundary Value Problems Of A Coupled System Of Nonlinear Fractional Hybrid Differential Equations, Yige Zhao, Yibing Sun

Turkish Journal of Mathematics

In this paper, we consider the existence and uniqueness for parametric boundary value problems of a coupled system of nonlinear fractional hybrid differential equations. By the fixed point theorem in Banach algebra, an existence theorem for parametric boundary value problems of a coupled system of nonlinear fractional hybrid differential equations is given. Further, a uniqueness result for parametric boundary value problems of a coupled system of nonlinear fractional hybrid differential equations is proved due to Banach's contraction principle. Further, we give three examples to verify the main results.


Two Nonzero Weak Solutions For A Quasilinear Kirchhoff Type Problem, LIN LI, STEPAN TERSIAN 2022 TÜBİTAK

Two Nonzero Weak Solutions For A Quasilinear Kirchhoff Type Problem, Lin Li, Stepan Tersian

Turkish Journal of Mathematics

We study the existence of two nonzero solutions for a class of quasilinear Kirchhoff problems. The approach is based on the variational methods. Our nonlinerity is contrast to some previous results is that superlinear growth at infinity.


Mathematical Analysis Of Local And Global Dynamics Of A New Epidemic Model, SÜMEYYE ÇAKAN 2022 TÜBİTAK

Mathematical Analysis Of Local And Global Dynamics Of A New Epidemic Model, Sümeyye Çakan

Turkish Journal of Mathematics

In this paper, we construct a new $SEIR$ epidemic model reflecting the spread of infectious diseases. After calculating basic reproduction number $% \mathcal{R}_{0}$ by the next generation matrix method, we examine the stability of the model. The model exhibits threshold behavior according to whether the basic reproduction number $\mathcal{R}_{0}$ is greater than unity or not. By using well-known Routh-Hurwitz criteria, we deal with local asymptotic stability of equilibrium points of the model according to $% \mathcal{R}_{0}.$ Also, we present a mathematical analysis for the global dynamics in the equilibrium points of this model using LaSalle's Invariance Principle associated with Lyapunov …


A Sequential Fractional Differential Problem Of Pantograph Type:Existence Uniqueness And Illustrations, SOUMIA BELARBI, ZOUBIR DAHMANI, MEHMET ZEKİ SARIKAYA 2022 TÜBİTAK

A Sequential Fractional Differential Problem Of Pantograph Type:Existence Uniqueness And Illustrations, Soumia Belarbi, Zoubir Dahmani, Mehmet Zeki̇ Sarikaya

Turkish Journal of Mathematics

In this study, a new class of sequential fractional differential problems of pantograph type is introduced. New existence and uniqueness criteria for the existence and uniqueness of solutions are discussed. Some existence results using Darbo's fixed point and measure of noncompactness are also studied. At the end, two illustrative examples are discussed.


A Refinement Of Newton And Maclaurin Inequalities Through Abstract Convexity, GÜLTEKİN TINAZTEPE, RAMAZAN TINAZTEPE 2022 TÜBİTAK

A Refinement Of Newton And Maclaurin Inequalities Through Abstract Convexity, Gülteki̇n Tinaztepe, Ramazan Tinaztepe

Turkish Journal of Mathematics

In this study, the refinements of Maclaurin's and Newton's inequalities are given. These refinements are obtained by applying the results on optimality conditions of abstract convex functions. When doing this, we obtain lower bounds for the solutions of some special rational equations.


Elliptical Kinematics Of The Accretive Surface Growth, ZEHRA ÖZDEMİR, GÜL GÜNER 2022 TÜBİTAK

Elliptical Kinematics Of The Accretive Surface Growth, Zehra Özdemi̇r, Gül Güner

Turkish Journal of Mathematics

The stresses within the soft tissue are not constant for some shell surfaces. They vary with position along the mantle edge. In this paper, we show that elliptical geometry is more convenient to describe this type of surface. Thus, we introduce the elliptical kinematics along an initial curve and construct some accretive surfaces with an elliptical cross-section. In fact, these surfaces are not only curves with an elliptical cross-sectional curve, but also the material points of the surface follow an elliptical trajectory during their formation. This situation can be easily explained through elliptical motion and elliptical quaternion algebra. Then, we …


Some Notes On Crossed Semimodules, SEDAT TEMEL 2022 TÜBİTAK

Some Notes On Crossed Semimodules, Sedat Temel

Turkish Journal of Mathematics

In this paper, we introduce the notion of lifting via a homomorphism of monoids for a crossed semimodule and give some properties. Further, we characterize actions and coverings of Schreier internal categories in the category Mon of monoids and prove the natural equivalence between their categories. Then, we prove that liftings of a certain crossed semimodule are naturally equivalent to the actions of Schreier internal category in Mon, where the Schreier internal category corresponds to the crossed semimodule. Finally, we give a relation between crossed semimodules and simplicial monoids.


On Extended Interpolative Single And Multivalued $F$-Contractions, İSA YILDIRIM 2022 TÜBİTAK

On Extended Interpolative Single And Multivalued $F$-Contractions, İsa Yildirim

Turkish Journal of Mathematics

The main objective of this paper is to study an extended interpolative single and multivalued Hardy-Rogers type $F$-contractions in complete metric spaces. We prove some fixed point theorems for such mappings. Further, we give an application to integral equations to verify our main results. The results presented in this paper improve the recent works of Karapinar et al. [12] and Mohammadi et al. [16].


Relation Between Matrices And The Suborbital Graphs By The Special Number Sequences, ÜMMÜGÜLSÜN AKBABA, ALİ HİKMET DEĞER 2022 TÜBİTAK

Relation Between Matrices And The Suborbital Graphs By The Special Number Sequences, Ümmügülsün Akbaba, Ali̇ Hi̇kmet Değer

Turkish Journal of Mathematics

under circuit and forest conditions. Special number sequences and special vertex values of minimal length paths in suborbital graphs have been associated in our previous studies. In these associations, matrix connections of the special continued fractions $\mathcal K (-1/-k)$, where $k\in \mathbb{Z}^{+}, \ k\geq 2$ with the values of the special number sequences are used and new identities are obtained. In this study, by producing new matrices, new identities related to Fibonacci, Lucas, Pell, and Pell-Lucas number sequences are found by using both recurrence relations and matrix connections of the continued fractions. In addition, the farthest vertex values of the …


A Köthe-Toeplitz Dual Of A Generalized Cesaro Difference Sequence Space, A Degenerate Lorentz Space, Their Corresponding Function Spaces And Fpp, VEYSEL NEZİR, NİZAMİ MUSTAFA 2022 TÜBİTAK

A Köthe-Toeplitz Dual Of A Generalized Cesaro Difference Sequence Space, A Degenerate Lorentz Space, Their Corresponding Function Spaces And Fpp, Veysel Nezi̇r, Ni̇zami̇ Mustafa

Turkish Journal of Mathematics

In 1970, Cesaro sequence spaces was introduced by Shiue. In 1981, Kızmaz defined difference sequence spaces for ${\ell }^{\infty }$, ${\mathrm{c}}_0$ and $\mathrm{c}$. Then, in 1983, Orhan introduced Cesaro difference sequence spaces. Both works used difference operator and investigated the Köthe-Toeplitz dual for the new Banach spaces they introduced. Later, various authors generalized these new spaces, especially the one introduced by Orhan. In this study, first we discuss the fixed point property for these spaces and for the corresponding function space of the Köthe-Toeplitz dual. Moreover, we consider another generalized space which is a degenerate Lorentz space because the spaces …


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