On the semilocal convergence analysis of a seventh order four step method for solving nonlinear equations

OMS-Vol. 8 (2024), Issue 1, pp. 39-45 Open Access Full-Text PDF
Samundra Regmi , Ioannis K. Argyros , Santhosh George and Christopher I. Argyros

Abstract:We provide a semi-local convergence analysis of a seventh order four step method for solving nonlinear problems. Using majorizing sequences and under conditions on the first derivative, we provide sufficient convergence criteria, error bounds on the distances involved and uniqueness. Earlier convergence results have used the eighth derivative not on this method to show convergence. Hence, limiting its applicability.

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Distribution of Prime Numbers and Fibonacci Polynomials

OMS-Vol. 8 (2024), Issue 1, pp. 31-38 Open Access Full-Text PDF
Vladimir Pletser

Abstract:Squares of odd index Fibonacci polynomials are used to define a new function \(\Phi\left(10^{n}\right)\) to approximate the number \(\pi\left(10^{n}\right)\) of primes less than \(10^{n}\). Multiple of 4 index Fibonacci polynomials are further used to define another new function \(\Psi\left(10^{n}\right)\) to approximate the number \(\Delta\left(\pi\left(10^{n}\right)\right)\) of primes having \(n\) digits and compared to a third function \(\Psi’\left(10^{n}\right)\) defined as the difference of the first function \(\Phi\left(10^{n}\right)\) based on odd index Fibonacci polynomials. These three functions provide better approximations of \(\pi\left(10^{n}\right)\) than those based on the classical \(\left(\frac{x}{log\left(x\right)}\right)\), Gauss’ approximation \(Li\left(x\right)\), and the Riemann \(R\left(x\right)\) functions.

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Euler’s and the taxi cab relations and other numbers that can be written twice as sums of two cubed integers

OMS-Vol. 8 (2024), Issue 1, pp. 25-30 Open Access Full-Text PDF
Vladimir PLETSER

Abstract:We show that Euler’s relation and the Taxi-Cab relation are both solutions of the same equation. General solutions of sums of two consecutive cubes equaling the sum of two other cubes are calculated. There is an infinite number of relations to be found among the sums of two consecutive cubes and the sum of two other cubes, in the form of two families. Their recursive and parametric equations are calculated.

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Existence and convergence of gamma matrices and their application to infinite series

OMS-Vol. 8 (2024), Issue 1, pp. 17-24 Open Access Full-Text PDF
Suresh Kumar Sahani, A.K. Thakur, Avinash Kumar and K. Sharma

Abstract:This study introduces theorems concerning matrix products, which delineate the transformations of sequences or series into other sequences or series, ensuring either the preservation of limits or the guarantee of convergence. Previous literature has explored the properties of matrices facilitating transformations between sequences, series, and their combinations, with detailed insights available in references [1,2,3].

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Some new results on w Up-algebras

OMS-Vol. 8 (2024), Issue 1, pp. 8-16 Open Access Full-Text PDF
Daniel A. Romano

Abstract:The concept of weak UP-algebras (shortly wUP-algebra) is an extension of the notion of UP-algebras introduced in 2021 by Iampan and Romano. In this report, an effective extension of a (weak) UP-algebra to a wUP-algebra is created. In addition to the previous one, the concept of atoms in wUP-algebras is introduced and their important properties are registered. Finally, the concept of wUP-filters in wUP-algebras was introduced and its connections with other substructures in wUP-algebras were analyzed.

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The skew constant and orthogonalities in Banach spaces

OMS-Vol. 8 (2024), Issue 1, pp. 1-7 Open Access Full-Text PDF
Yin Zhou, Qichuan Ni and Qi Liu

Abstract:In normed spaces, Birkhoff orthogonality and isosceles orthogonality can be used to characterize space structures, and many scholars have introduced geometric constants to quantitatively describe the relationship between these two types of orthogonality. This paper introduces a new orthogonal relationship – Skew orthogonality – and proposes a new geometric constant to measure the “distance” of difference between skew orthogonality and Birkhoff orthogonality in normed spaces. In the end, we provide some examples of specific spaces.

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Calculating degree-based topological indices and m-polynomials for various interconnection networks

ODAM-Vol. 7 (2024), Issue 1, pp. 21 – 38 Open Access Full-Text PDF
Noha Mohammad Seyam, Mohammed Ali Alghamdi and Adnan Khalil

Abstract: There are three different kinds of topological indices: spectrum-based, degree-based, and distance-based. We presented the \(K\)-swapped network for \(t\)-regular graphs in this study. We also computed various degree-based topological indices of the \(K\)-swapped network for \(t\)-regular graphs, eye, and \(n\)-dimensional twisted cube network. The metrics used to analyze the abstract structural characteristics of networks are called topological indices. We also calculate each of the aforementioned networks M-polynomials. A graph can be used to depict an interconnection network’s structure. The processing nodes in the network are represented by vertices, while the links connecting the processor nodes are represented by edges. We can quickly determine the diameter and degree between the nodes based on the graph’s topology. A key component of graph theory are graph invariants, which identify the structural characteristics of networks and graphs. Furthermore described by graph invariants are computer, social, and internet networks.

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Edge hub number of fuzzy graphs

ODAM-Vol. 7 (2024), Issue 1, pp. 11 – 20 Open Access Full-Text PDF
Saad Tobaili, Haifa Ahmed and Mohammed Alsharafi

Abstract: Shadi I.K et al. [1] introduced the edge hub number of graphs. This work extends the concept to fuzzy graphs. We derive several properties of edge hub number of fuzzy graphs and establish some relations that connect the new parameter with other fuzzy graph parameters. Also, some bounds of such a parameter are investigated. Moreover, we provide empirical evidence examples to elucidate the behavior and implications of edge hub number of fuzzy graph parameters.

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Covering and 2-degree-packing numbers in graphs

ODAM-Vol. 7 (2024), Issue 1, pp. 1 – 10 Open Access Full-Text PDF
Carlos A. Alfaro, Christian Rubio-Montiel and Adrián Vázquez Ávila

Abstract: In this paper, we give a relationship between the covering number of a simple graph \(G\), \(\beta(G)\), and a new parameter associated to \(G\), which is called 2-degree-packing number of \(G\), \(\nu_2(G)\). We prove that \[\lceil \nu_{2}(G)/2\rceil\leq\beta(G)\leq\nu_2(G)-1,\] for any simple graph \(G\), with \(|E(G)|>\nu_2(G)\). Also, we give a characterization of connected graphs that attain the equalities.

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Chromatically unique \(6\)-bridge graph \(\theta (r,r,s,s,t,u)\)

ODAM-Vol. 6 (2023), Issue 3, pp. 41 – 56 Open Access Full-Text PDF
Syed Ahtsham Ul Haq Bokhary and Shehr Bano

Abstract: Let \(A\) and \(B\) be two graph and \(P(A,z)\) and \(P(B,z)\) are their chromatic polynomial, respectively. The two graphs \(A\) and \(B\) are said to be chromatic equivalent denoted by \( A \sim B \) if \(P(A,z)=P(B,z)\). A graph \(A\) is said to be chromatically unique(or simply \(\chi\)- unique) if for any graph \(B\) such that \(A\sim B \), we have \(A\cong B\), that is \(A\) is isomorphic to \(B\). In this paper, the chromatic uniqueness of a new family of \(6\)-bridge graph \(\theta(r,r,s,s,t,u)\) where \(2\leq r\leq s \leq t\leq u\) is investigated.

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