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Latest Published Articles

Block Sombor index of a graph and its matrix representation

ODAM-Vol. 6 (2023), Issue 1, pp. 1 – 11 Open Access Full-Text PDF
Vyshnavi Devaragudi and Basavaraju Chaluvaraju

Abstract:The Sombor index has gained lot of attention in the recent days for its mathematical properties and chemical applicabilities. Here, we initiated the novel block number version of the classical Sombor index and its matrix representation of a graph. The Block Sombor index \(BS(G)\) is defined as the sum total of square root of the sum of squares of block numbers of adjacent vertices, where the block number of a vertex is the number of blocks to which that vertex belongs to. The main purpose of this paper is to obtain some bounds and characterizations of \(BS(G)\) and its Block Sombor energy \(E_{BS}\). Also, we estimate some properties of spectral radius of Block Sombor matrix \(A_{BS}(G)\).

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Statistical modelling of maximum temperature in Rwanda using extreme value analysis

OMS-Vol. 7 (2023), Issue 1, pp. 180 – 195 Open Access Full-Text PDF
Edouard Singirankabo, Emmanuel Iyamuremye, Alexis Habineza and Yunvirusaba Nelson

Abstract: This study aims to model the statistical behaviour of extreme maximum temperature values in Rwanda. To achieve such an objective, the daily temperature data from January 2000 to December 2017 recorded at nine weather stations collected from the Rwanda Meteorological Agency were used. The two methods, namely the block maxima (BM) method and the Peaks Over Threshold (POT), were applied to model and analyse extreme temperatures in Rwanda. Model parameters were estimated, while the extreme temperature return periods and confidence intervals were predicted. The model fit suggests that Gumbel and Beta distributions are the most appropriate for the annual maximum daily temperature. Furthermore, the results show that the temperature will continue to increase as estimated return levels show it.

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Exact solutions of paraxial wave dynamical model with Kerr law non-linearity using analytical techniques

OMS-Vol. 7 (2023), Issue 1, pp. 172 – 179 Open Access Full-Text PDF
Naeem Ullah

Abstract: Using the Kudryashov and Tanh methods, we have obtained novel exact solutions for the Paraxial Wave Dynamical Equation with Kerr law, including various types of wave solutions. These distinct types of wave solutions have important applications in physics and engineering, and their physical characteristics are well defined. These outcomes are a substantial innovation in the study of water waves in mathematical physics and engineering phenomena. The results we have acquired demonstrate the power and effectiveness of the present techniques.

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Effects of thermal dispersion on transient free convective flow in vertical porous channel filled with porous material

OMS-Vol. 7 (2023), Issue 1, pp. 160 – 171 Open Access Full-Text PDF
Babatunde Aina and Basant K. Jha

Abstract: In this work, the effect of suction/injection on transient free convective flow in vertical porous (suction/injection on the channel surfaces) channel filled with porous material in the presence of thermal dispersion was studied. The Boussinesq assumption is applied and the nonlinear governing equations of motion and energy are developed. The time dependent problem is solved using implicit finite difference method while steady state problem is solved by perturbation technique method. The solution obtained is graphically represented and the effects of suction/injection, time, Darcy number, thermal dispersion, and Prandtl number on the fluid flow and heat transfer characteristics. During the course of computation, an excellent agreement was found between the well-known steady state solutions sand transient solutions at large value of time. Furthermore, the time required to reach steady state velocity and temperature field strongly dependent on suction/injection parameter, Prandtl number and thermal dispersion parameter. The introduction of suction/injection has distorted the symmetric nature of the flow formation.

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Vector bundles associated to monads on cartesian products of projective spaces

OMS-Vol. 7 (2023), Issue 1, pp. 148 – 159 Open Access Full-Text PDF
Damian M Maingi

Abstract: In this paper we establish the existence of monads on cartesian products of projective spaces. We give the necessary and sufficient conditions for the existence of monads on \(\mathbf{P}^1\times\cdots\times \mathbf{P}^1\). We construct vector bundles associated to monads on \(X=\mathbf{P}^n\times\mathbf{P}^n\times\mathbf{P}^m\times\mathbf{P}^m\). We study these vector bundles associated to monads on \(X\) and prove their stability and simplicity.

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New Simpson’s type inequalities via \((\alpha_1, m_1)\) -\((\alpha_2, m_2)\)- preinvexity on the coordinates in both the first and second sense

OMS-Vol. 7 (2023), Issue 1, pp. 135 – 147 Open Access Full-Text PDF
Seth Kermausuor

Abstract: In this paper, we established a new integral identity for twice partially differentiable functions. As a consequence, we established some new Simpson’s type integral inequalities for functions of two independent variables whose mixed partial derivative is bounded and \((\alpha_1, m_1)-(\alpha_2, m_2)\)-preinvex on the coordinates in both the first and second sense.

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BOOK-foundations-of-mathematical-analysis-and-semigroups-theory
BOOK - NULL CONTROLLABILITY OF DEGENERATE AND NON-DEGENERATE SINGULAR PARABOLIC