Mathematical Theory and Modeling
http://www.iiste.org/Journals/index.php/MTM
<p><span id="internal-source-marker_0.04939836589619517"><span id="internal-source-marker_0.04939836589619517">Mathematical Theory and Modeling </span>is a peer reviewed journal published by IISTE. The journal publishes original papers at the forefront of mathematical theories, modelings, and applications. The journal is published in both printed and online versions. The online version is free access and download.</span></p><p><span>IISTE is member of <a href="http://www.crossref.org/01company/17crossref_members.html">CrossRef</a>.<br /></span></p>en-USMathematical Theory and Modeling2224-5804Some Root Finding With Extensions to Higher Dimensions
http://www.iiste.org/Journals/index.php/MTM/article/view/36723
<p>Root finding is an issue in scientific computing. Because most nonlinear problems in science and engineering can be considered as the root finding problems, directly or indirectly. The research in numerical modeling for root finding is still going on. In this study, fixed point iterative methods for solving simple real roots of nonlinear equations, which improve convergence of some existing methods, are thorough. Derivative estimations up to the third order (in root finding, some recent ideas) are applied in Taylor’s approximation of a nonlinear equation by a cubic model to achieve efficient iterative methods. We may also discuss possible extensions to two dimensions and consider Newton’s method and Halley’s method in 1D and 2D problem solving. Several examples for test of efficiency and convergence analyses using C++ are offered. And some engineering applications of root finding are conferred. Graphical demonstrations are supported with matlab basic tools.<strong></strong></p> <p class="KeywordsHeader">Keywords: engineering applications, derivative estimations, iterative methods, simple roots, Taylor’s approximation.</p>Tekle Gemechu7On M-Compact Ring
http://www.iiste.org/Journals/index.php/MTM/article/view/36724
<p>In the present paper, we have introduced some new definitions On <em>M-cover</em> <em>ring</em>, <em>M-compact ring</em>, <em>weakly M-compact ring, weakly M-compact c. ring</em><em>,</em><em> M-compact c. ring, M-compact locally ring</em><em> and </em><em>M-compact strong locally ring</em>, we obtain some<strong> </strong>examples and results related to <em>M-cover ring</em>, <em>M-compact ring, weakly M-compact ring, weakly M-compact c. ring</em><em>,</em><em> M-compact c. ring, M-compact locally ring</em> and <em>M-compact</em> <em>strong locally ring</em>.</p> <p><strong>Keywords:</strong> <em>rings</em>, <em>M-cover ring, M-compact ring, ring </em><em>homomorphism</em><em>, ring </em><em>isomorphism.</em></p>Mohammed H. Lafta7LOGISTIC MIXED MODELLING OF DETERMINANTS OF INTERNATIONAL MIGRATION FROM THE SOUTHERN ETHIOPIA: SMALL AREA ESTIMATION APPROACH
http://www.iiste.org/Journals/index.php/MTM/article/view/36725
<p>The main objective of this study is to investigate socio-demographic and economic characteristics of a household on international migration and to estimate small area proportions at district and enumeration area level. Migration status refers to whether a household has at least one member who ever migrated abroad or not. A total of 2288 data are collected from sixteen randomly sampled districts in Hadiya and Kembata-Tembaro zonal areas, Southern Ethiopia. Several versions of the binary logistic mixed models, as special cases of the generalized linear mixed model, are analyzed and compared. The findings of the study reveal that about 39.4% of the households have at least one international migrant, and the rest 60.6% have no such migrants. Based on analysis of the generalized linear model and stepwise variable selection, four predictors are found to be significantly related to household migration status at 5% significance level. These are age, occupation, and educational level of household head and family size. Then twelve mixed models are analyzed and compared. The best fitting model to the data is found to be the logistic mixed regression model consisting of the six predictors with age nested within districts as random effects. Area or district specific random effect has variance of 1.6180. The district level random variation founded on final model with six predictor variables about the presence of migrant in the households such as the variation between districts is 33% and variation within the district is 67%. From analysis of the final model, it is found that the likelihood of a household of having international migrant increases with head's age and family size. An increase of family size by one person increases the log odds of having migrant by 0.131 indicating that large family size is one of the determinants for migration in the study area. The migration prevalence varies among the zones, the districts and the enumeration areas. Household characteristics: age, educational level and occupation of head, and family size are determinants of international migration. Community based intervention is needed so as to monitor and regulate the international migration for the benefits of the society.</p> <p><strong><em>Keywords</em></strong>: GLM, GLMM, Migration, Mixed Logistic, Small Area Estimation</p>Tsedeke Lambore Gemecho7ANALYSIS OF HEAT AND MASS TRANSFER RATES OF HYDROMAGNETIC TURBULENT FLUID FLOW OVER AN IMMERSED INFINITE HORIZONTAL CYLINDER WITH HALL CURRENT
http://www.iiste.org/Journals/index.php/MTM/article/view/36726
<p>A mathematical model of hydromagnetic turbulent boundary layer fluid flow past a horizontal infinite cylinder with Hall current is considered. The cylinder is placed in cross flow with the fluid. The fluid flow is impulsively started and the flow problem is subsequently analysed. The flow is modeled using the momentum, energy and concentration conservation equations. The Reynolds stresses arising due to turbulence in the conservation equations are resolved using Prandtl mixing length hypothesis. The equations are then solved by a finite difference method. The effects of flow parameters on the primary velocity, secondary velocity, temperature and concentration profiles are investigated. It is found that velocity profiles increase with increase in Hall parameter and temperature and concentration profiles increase with increase in magnetic parameter.</p> <p><strong>Key words:</strong> Turbulent flow, Hall current, cylinder, hydromagnetic, convection, finite difference</p>W. O. MUKUNAJ. K. KWANZAJ. K. SIGEYJ. A. OKELLO7