Browsing by Author "R. O. Ayinla"

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    Estimates for a class of analytic and univalent functions connected with quasi-subordination
    (Nigerian Society of Physical Sciences, 2024) R. O. Ayinla; A. O. Lasode
    Geometric Function Theory, an active field of study that has its roots in complex analysis, has gained an impressive attention from many researchers. This occurs largely because it deals with the study of geometric properties of analytic (and univalent) functions where many of its applications spread across many fields of mathematics, mathematical physics and engineering. Notable areas of application include conformal mappings, special functions, orthogonal polynomials, fluid flows in physics, and engineering designs. The investigations in this paper are on a subclass of analytic and univalent functions defined in the unit disk Ω and denoted by Qαq(m). The definition of the new class encompasses some well-known subclasses of analytic and univalent functions such as the classes of starlike functions, Yamaguchi functions, and Ma-Minda functions. Two key mathematical principles involved in the definition of the class are the principles of Taylor’s series and quasi-subordination. Some of the investigations carried out on functions f ∈ Qαq(m) are however, the upper estimates for some initial bounds, the solution to the well-known Fekete-Szegö problem and the upper estimate for a Hankel determinant.
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    Exploring Enhanced Conjugate Gradient Methods: A Novel Family of Techniques for Efficient Unconstrained Minimization
    (2024) O. B. Onuoha; R. O. Ayinla; G. Egenti; O. E. Taiwo
    Given that the conjugate gradient method (CGM) is computationally efficient and user-friendly, it is often used to address large-scale, unconstrained minimization issues. Numerous researchers have created new conjugate gradient (CG) update parameters by modifying the initial set, also referred to as classical CGMs. This has resulted in the development of several hybrid approaches. This work’s major goal is to create a new family of techniques that can be used to create even more new methods. Consequently, Hestenes-Stiefel’s update parameter and a new family involving Polak-Ribiere-Polyak and Liu-Storey CGMs are considered. By changing the parameters of this CGM family, a novel approach that possesses sufficient descent characteristics is obtained. A numerical experiment including many unconstrained minimization problems (UMP) is carried out to assess the novel method’s efficacy compared to existing approaches. The result reveals that the new CG approach performs better than the current ones.
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    New Result for Strongly Starlike Functions
    (Scientific Research Publishing, 2017-03-24) R. O. Ayinla; T. O. Opoola
    n this paper, using Salagean differential operator, we define and investigate a new subclass of univalent functions S^(α) β . We also establish a characterization property for functions belonging to the class S^(α) β .
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    Some coefficient problems of a class of close-to-star functions of type α defined by means of a generalized differential operator
    (2022) A. O. Lasode; A. O. Ajiboye; R. O. Ayinla
    In this investigation, we studied a class of Bazileviˇc type close-to-star functions which is defined by a generalized differential operator. The new class generalizes many known and new subclasses of close-to-star functions. Some of the investigated properties are the coefficient bounds and the Fekete-Szeg¨o functional. Our results extend some known and new ones.