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Now showing 1 - 10 of 13
  • Article
    Citation - WoS: 2
    Citation - Scopus: 3
    Lyapunov-Type Inequalities for Lidstone Boundary Value Problems on Time Scales
    (Springer-verlag Italia Srl, 2020) Agarwal, Ravi P.; Oguz, Arzu Denk; Ozbekler, Abdullah
    In this paper, we establish new Hartman and Lyapunov-type inequalities for even-order dynamic equations x.2n (t) + (-1)n-1q(t) xs (t) = 0 on time scales T satisfying the Lidstone boundary conditions x.2i (t1) = x.2i (t2) = 0; t1, t2. [t0,8) T for i = 0, 1,..., n - 1. The inequalities obtained generalize and complement the existing results in the literature.
  • Article
    Citation - WoS: 141
    Citation - Scopus: 144
    Uniqueness of Solution for Higher-Order Nonlinear Fractional Differential Equations With Multi-Point and Integral Boundary Conditions
    (Springer-verlag Italia Srl, 2021) Sevinik-Adiguzel, Rezan; Aksoy, Umit; Karapinar, Erdal; Erhan, Inci M.
    This study is devoted to the development of alternative conditions for existence and uniqueness of nonlinear fractional differential equations of higher-order with integral and multi-point boundary conditions. It uses a novel approach of employing a fixed point theorem based on contractive iterates of the integral operator for the corresponding fixed point problem. We start with developing an existence-uniqueness theorem for self-mappings with contractive iterate in a b-metric-like space. Then, we obtain the unique solvability of the problem under suitable conditions by utilizing an appropriate b-metric-like space.
  • Editorial
    Pontine Capillary Telangiectasia Mimicking Active Demyelinating Plaque in a Patient With Multiple Sclerosis
    (Springer-verlag Italia Srl, 2023) Koksal, Ali; Kiziloglu, Alper; Ogul, Hayri
    [No Abstract Available]
  • Article
    Citation - WoS: 51
    Citation - Scopus: 58
    F-Contraction Mappings on Metric-Like Spaces in Connection With Integral Equations on Time Scales
    (Springer-verlag Italia Srl, 2020) Agarwal, Ravi P.; Aksoy, Umit; Karapinar, Erdal; Erhan, Inci M.
    In this paper we investigate the existence and uniqueness of fixed points of certain (phi,F)-type contractions in the frame of metric-like spaces. As an application of the theorem we consider the existence and uniqueness of solutions of nonlinear Fredholm integral equations of the second kind on time scales. We also present a particular example which demonstrates our theoretical results.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 4
    A Sturm Comparison Criterion for Impulsive Hyperbolic Equations
    (Springer-verlag Italia Srl, 2020) Ozbekler, Abdullah; Isler, Kubra Uslu
    In this paper, we investigate the Sturmian comparison theory for hyperbolic equations with fixed moments of effects. The results obtained extend the results of those existing in the literature for Sturmian comparison theory on ordinary and impulsive differential equations to impulsive hyperbolic equations.
  • Article
    Citation - WoS: 8
    Citation - Scopus: 8
    Berinde Mappings in Ordered Metric Spaces
    (Springer-verlag Italia Srl, 2015) Karapinar, Erdal; Sadarangani, Kishin
    Recently, Samet and Vetro proved a fixed point theorem for mappings satisfying a general contractive condition of integral type in orbitally complete metric spaces (Samet and Vetro, Chaos Solitons Fractals 44:1075-1079, 2011). Our aim in this paper is to present a version of the results obtained in the above mentioned paper in the context of ordered metric spaces. Some examples are presented to distinguish our results from the existing ones.
  • Article
    Citation - WoS: 13
    Citation - Scopus: 13
    Best Proximity Point Results in Dislocated Metric Spaces Via r-functions
    (Springer-verlag Italia Srl, 2018) Gholizadeh, Leila; Karapinar, Erdal
    In this paper, we investigate the existence of best proximity of R-contractions in the frame of dislocated metric spaces. We also propose some conditions to guarantee the uniqueness of best proximity point for such contractions. We consider an illustrative example to support the given results. This result generalizes a number of recent results on the topic in the literature.
  • Article
    Citation - WoS: 13
    Citation - Scopus: 16
    A Remark on "existence and Uniqueness for a Neutral Differential Problem With Unbounded Delay Via Fixed Point Results F-Metric Spaces"
    (Springer-verlag Italia Srl, 2019) Aydi, Hassen; Karapinar, Erdal; Mitrovic, Zoran D.; Rashid, Tawseef
    Very recently, Hussain and Kanwal (Trans A Razmadze Math Inst 172(3): 481-490, 2018) proved some (coupled) fixed point results in this setting for a -.-contractive mappings on the setting of F-metric spaces that was initiated by Jleli and Samet (Fixed Point Theory Appl 2018: 128, 2018). In this note, we underline that the proof of Hussain and Kanwal (Trans A Razmadze Math Inst 172(3): 481-490, 2018) has a gap. We provide two examples to illustrate our observation. We also correct the proof and improved the result by replacing a-admissibility by orbital a-admissibility.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 4
    Examining the Effects of Non-Immersive Virtual Reality Game-Based Training on Knee Hyperextension Control and Balance in Chronic Stroke Patients: a Single-Blind Randomized Controlled Study
    (Springer-verlag Italia Srl, 2024) Korkusuz, Suleyman; Taskin, Gulsen; Korkusuz, Buesra Seckinogullari; Ozen, Melike Sumeyye; Yuruk, Zeliha Ozlem
    Background Post-stroke hemiparesis can lead to decreased mobility, gait disturbances, impaired balance, postural instability, limitations in activities of daily living (ADL), and long-term disability. Aims The aim of this study was to examine the effect of non-immersive virtual reality game-based training (nIVRGT) in addition to conventional rehabilitation in stroke patients on dynamic balance, knee hyperextension control, and ADL. Methods Twenty-five chronic stroke patients aged between 51 and 70 were included in the study. Stroke patients were randomized to a control group (n = 12) and a study group (n = 13). Individuals in control group participated conventional physiotherapy and rehabilitation program for 60 min, 3 days a week for 6 weeks. individuals in the study group received 40 min of conventional physiotherapy and rehabilitation program plus 20 min nIVRGT. Functional Reach Test, Timed Up and Go Test, Computerized Gait Evaluation System and Barthel Index were used in the evaluation. Result The study group improved significantly in dynamic balance, knee control, and ADL (p < 0.05). In the control group, significant improvements were observed in dynamic balance and knee control (p < 0.05), except ADL (p > 0.05). The study group improved in dynamic balance compared with the control group (p < 0.05). Knee control and ADL improved similarly in both groups (p > 0.05). Conclusion Our results showed that conventional and additional nIVRGT rehabilitation improved dynamic balance and knee hyperextension control in chronic stroke. However, it was observed that the non-immersive virtual reality (nIVR) approach was more effective in improving dynamic balance in stroke patients than conventional rehabilitation alone.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Lyapunov type inequalities for second-order forced dynamic equations with mixed nonlinearities on time scales
    (Springer-verlag Italia Srl, 2017) Agarwal, Ravi P.; Cetin, Erbil; Ozbekler, Abdullah
    In this paper, we present some newHartman and Lyapunov inequalities for second-order forced dynamic equations on time scales T with mixed nonlinearities: x(Delta Delta)(t) + Sigma(n)(k=1) qk (t)vertical bar x(sigma) (t)vertical bar (alpha k-1) x(sigma) (t) = f (t); t is an element of [t(0), infinity)(T), where the nonlinearities satisfy 0 < alpha(1) < ... < alpha(m) < 1 < alpha(m+1) < ... < alpha(n) < 2. No sign restrictions are imposed on the potentials qk, k = 1, 2, ... , n, and the forcing term f. The inequalities obtained generalize and compliment the existing results for the special cases of this equation in the literature.