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Latest Published Articles

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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Multiplicity results for a class of nonlinear singular differential equation with a parameter

OMA-Vol. 7 (2023), Issue 2, pp. 38 – 44 Open Access Full-Text PDF
Shaowen Li

Abstract: This paper gives sufficient conditions for the existence of positive periodic solutions to general indefinite singular differential equations. Furthermore, under some assumptions we show the existence of two positive periodic solutions. The methods used are Krasnoselski\(\breve{\mbox{i}}\)’s-Guo fixed point theorem and the positivity of the associated Green’s function.

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BOOK - NULL CONTROLLABILITY OF DEGENERATE AND NON-DEGENERATE SINGULAR PARABOLIC