Mathematical Sciences

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Landau theoretical interpretation of domain and domain walls in ferroelectric ferroics
(Asian Research Publishing Network, 2006) Rwenyagila, E. R.; Mwanga, S. F.
In this paper some behaviors of domain and domain walls in perovskite ferroics were theoretically investigated. Landau type theory was used to examine the phenomenological properties of domains and domain walls in ferroelectric perovskite materials. Landau predictions on the prototype ferroelectric BaTiO3 showed that it has a stable tetragonal structure at room temperature. The number of domains in the three ferroelectric phases of BaTiO3 was also calculated. The results confirmed six, eight and twelve domain states in the tetragonal, rhombohedral and orthorhombic structures of BaTiO3, respectively. The respective spontaneous polarization and domain wall thickness in the stable tetragonal BaTiO3 have values of 0.26 Cm-2 and 1.63nm at room temperature. Analytical and numerical solutions for the relationship between temperature and domain wall thickness and for the spatial distribution of polarizations inside the domain wall are also determined and discussed.
A logistic regression model of customer satisfaction of airline
(Macrothink Institute, 2012) Peter, Josephat; Abbas, Ismail
Evaluation of customer satisfaction differs from one study to another. Studies have been differing with their focus and coverage. Most of studies focused on evaluating factors influencing customer satisfaction or associate customer satisfaction and quality of services. This paper used logistic regression to develop customer satisfaction model for Precision Air. Five dimensions or variables have been considered: on time performance; aircraft safety; schedule integrity; on board services; and customer service. Data used in this paper were collected from four major regions with many flights. These include Dar es Salaam, Mwanza, Arusha and Kilimanjaro. A sample size of 272 passengers was selected. Convenience sampling was used to select the respondents. Primary data were collected in the field through questionnaire. Findings showed that out of the five independent variables only one variable is negatively related with satisfaction of airline passengers (customer services). In contrast, on time performance was satisfactory variable by most of passengers compared to the rest of explanatory variables. Airline safety, schedule integrity and on board services are positively related with passengers satisfaction. Relationship between customer services and satisfaction are negatively related which implies that, there is a need of finding strategies to improve customer services to customers. The paper recommends that the airline should maintain and improve on time performance as this is crucial variable for passenger’s satisfaction but other variables need more improvement.
Utilization of client service charter: an experience from Dodoma municipal council–Tanzania
(Diva Enterprises Pvt. Ltd.(DE), 2012) Likangaga, R.; Josephat, P.
Inconsistency of Clients Service Charter (CSC) effects and lack of literature on CSC influenced this study to be conducted by examining the utilization of CSC in Local Authorities (LAs) with particular reference to Dodoma Municipal Council. This study employed a case study design. A sample size of 118 clients was purposively selected. The sample comprised 60 internal customers’ and 58 external customers. The study concludes that there is poor utilization of CSC in DMC because since the establishment of the charter, it has not been made public. In addition there is no any effort taken by the DMC management to make it operational. The study found that despite CSC being not implemented, majority of the external customers were satisfied by the services provided by DMC. On the other hand, majority of the internal customers were not satisfactory by the services offered by DMC.
Job and work attitude determinants: An application of multivariate analysis.
(Macrothink Institute, 2012) Josephat, P.; Ismail, A.
This paper analyzed variables that used to measure job and work attitude of an employee in an organization. Analysis was done using multivariate analysis. Data used was collected from Dodoma and Musoma municipalities as the municipalities were randomly selected. A sample size of the study was 118. Cross sectional research design was adopted. The study found that there are five factors which influence job and work attitude. These are satisfaction, independency, teamwork, freedom of expression and supervisory relationship. All these factors are significantly positive related to dependent variable job and work attitude.
Statistical measurement of service quality in Tanzania industries: A case of Said Salim Bakhresa & Co Ltd
(Macrothink Institute, 2012) Ismail, A.; Josephat, P.
The study aimed to use statistical techniques to measure quality of services produced by Said Salim Bakhresa & Co Ltd. The study was conducted among wholesalers and bakeries who sell wheat flour produced by the company. These were selected from four different locations representing the major towns where the wheat flour and its products are widely consumed. These are Dar es Salaam, Morogoro, Arusha, Moshi and Tanga. Sample size for the study was 434. The study employed the cross-sectional study design and prestructured questionnaire was used to collect data. Factor analysis and regression analysis are statistical techniques performed. From eleven attributes outlined by ISO: 9000: 2008, the factor analysis formed four components: product quality; packaging; timeliness and promptness; and customer care. The findings show that all the components achieved good quality level because all have quality scale index less than 2.99. Regression analysis was adopted to generate ISO-Quality model, model shows that among the four components of qualities, two components (product quality and customer care) are statistically significant related with the company being ISO certified. In general product quality and packaging seem to perform better than the rest of the components.
A review of simple model problems in continuum mechanics with internal body forces
(The University of Dodoma, 2013) Hilal, Awena M.
This study was put in place in order to review simple model problems in continuum mechanics with internal body forces. The main objective of this study is to analyze simple model problems in continuum mechanics with internal body forces, which include the steady flow between parallel plates with internal body forces, which include review of internal body forces with its applications, internal body forces and moments, string with internal body forces, membrane with internal body forces, elasticity with internal body forces, the steady flow between parallel plates with internal body forces, steady flow in a pipe with internal body forces, steady flow between concentric cylinders with internal body forces and Bernoulli equation with internal body forces. In its execution, the study utilized desktop research to enable the collection of information needed for the analysis of simple model problems in continuum mechanics with internal body forces.
Group acceptance sampling plans for resubmitted lots for life tests based on half logistic distribution
(Renmin University of China, 2014) Rao, Srinivasa G.; Rao, Srinivasa B.
In this article, a Half Logistic Distribution (GASP) for lot resubmitting is developed to ensure quality of the product lifetime assuming that the product’s lifetime follows the half logistic distribution. The parameters of the GASP are determined by satifying the specified producer’s and consumer’s risks according to the experiment termination time and the number of testers. A comparison between this proposed group sampling and the ordinary group sampling plan is discussed. This proposed plan is justified with an illustration.
Quark star model with charged anisotropic matter
(Springer, 2014) Sunzu, J. M.; Maharaj., S. D.; Ray, S.
We find two new classes of exact solutions to the Einstein-Maxwell system of equations. The matter distribution satisfies a linear equation of state consistent with quark matter. The field equations are integrated by specifying forms for the measure of anisotropy and a gravitational potential which are physically reasonable. The first class has a constant potential and is regular in the stellar interior. It contains the familiar Einstein model as a limiting case and we can generate finite masses for the star. The second class has a variable potential and singularity at the center. A graphical analysis indicates that the matter variables are well behaved.
Some simple models for quark stars
(Springer, 2014) Maharaj, S. D.; Sunzu, J. M.; Ray, S.
We find two new classes of exact solutions for the Einstein-Maxwell equations. The solutions are obtained by considering charged anisotropic matter with a linear equation of state consistent with quark stars. The field equations are integrated by specifying forms for the measure of anisotropy and a gravitational potential which are physically reasonable. The solutions found generalize the Mark-Harko model and the Komathiraj-Maharaj model. A graphical analysis indicates that the matter variables are well behaved.
Asymptotic behavior of solutions of matrix lyapunov integro differential equations
(Korean Journal Publishing Service, 2014) Sarma, Goteti V.; Hugo, Alfred
The asymptotic behavior of solutions of Lyapunov type matrix Volterra integro differential equation, in which the coefficient matrices are not stable, is studied by the method of reduction.
Knowledge and perception on tuberculosis transmission in Tanzania: Multinomial logistic regression analysis of secondary data
(2014) Ismail, A.; Josephat, P.
Tuberculosis (TB) is one of the most important public health problems in Tanzania and was declared as a national public health emergency in 2006. Community and individual knowledge and perceptions are critical factors in the control of the disease. The objective of this study was to analyze the knowledge and perception on the transmission of TB in Tanzania. Multinomial Logistic Regression analysis was considered in order to quantify the impact of knowledge and perception on TB. The data used was adopted as secondary data from larger national survey 2007-08 Tanzania HIV/AIDS and Malaria Indicator Survey. The findings across groups revealed that knowledge on TB transmission increased with an increase in age and level of education. People in rural areas had less knowledge regarding tuberculosis transmission compared to urban areas [OR=0.7]. People with the access to radio [OR=1.7] were more knowledgeable on tuberculosis transmission compared to those who did not have access to radio. People who did not have telephone [OR=0.6] were less knowledgeable on tuberculosis route of transmission compared to those who had telephone. The findings showed that socio-demographic factors such as age, education, place of residence and owning telephone or radio varied systematically with knowledge on tuberculosis transmission.
New models for quark stars with charge and anisotropy
(2014) Sunzu, J. M.
We find new classes of exact solutions for the Einstein-Maxwell field equations. The solutions are obtained by considering charged anisotropic matter with a linear equation of state consistent with quark stars. The field equations are integrated by specifying forms for the measure of anisotropy and one of the gravitational potentials which are physically reasonable. A general feature of our models is that isotropic pressures are regained when certain parameters vanish; this behaviour is missing in most previous treatments. Particular models found in our results generalize the models of Mak and Harko, Komathiraj and Maharaj, Misner and Zapolsky, and the earlier results of Einstein. The graphical and physical analyses indicate that the gravitational potentials, the matter variables, the electric field and the mass are well behaved. In performing physical analysis we regain masses and radii of stellar objects consistent with observations. It is also shown that other masses and radii may be generated which are in acceptable ranges consistent with observed values of stellar objects. In particular we have established that our model is consistent with the stellar object SAXJ1808.4-3658. A study of the mass-radius relation indicates the effect of the electromagnetic field and anisotropy on the mass of the relativistic star.
Charged anisotropic models for quark stars
(Springer, 2014) Sunzu, J. M.; Maharaj, S. D.; Ray, S.
We perform a detailed physical analysis for a class of exact solutions for the Einstein-Maxwell equations. The linear equation of state consistent with quark stars has been incorporated in the model. The physical analysis of the exact solutions is performed by considering the charged anisotropic stars for the particular nonsingular exact model obtained by Maharaj, Sunzu and Ray. In performing such an analysis we regain masses obtained by previous researchers for isotropic and anisotropic matter. It is also indicated that other masses and radii may be generated which are in acceptable ranges consistent with observed values of stellar objects. A study of the mass-radius relation indicates the effect of the electromagnetic field and anisotropy on the mass of the relativistic star
A study of existence results on two point boundary value problem by fixed point method, monotone iterative technique and solution matching techniques
(The University of Dodoma, 2015) Afyusisye, Omary
The study of existence results on two point boundary value problems by fixed point methods, monotone iterative techniques, matching solution techniques and integral boundary conditions has been put in place in order to provide a broad understanding to the existence of two point boundary value problems by fixed point methods, monotone iterative techniques and solution matching techniques. The two point boundary value problem for ordinary differential equation has an important role in solving boundary value problems of Ordinary second order differential equations. Also play a great role in solving second-order boundary value problem with integral boundary conditions. The solutions of some linear ODE and boundary integral conditions can be denoted by Green's Function. Some BVP of nonlinear Differential Equation can be transformed into nonlinear integral equations by the kernel of which are Green's Functions of corresponding linear differential equations. The integral can be solved to investigate the property of the positive solutions. The main objective of the study of two point boundary value problems by fixed point methods, monotone iterative techniques, solution matching techniques and integral boundary conditions is to apply in solving positive solutions integral equations and second order differential equation. In this paper we consider the two point boundary value problem for second order linear differential equation (ODE) and integral boundary conditions with some positive solutions. As application, we study the fixed point methods and integral boundary conditions to find the existence of positive solutions.
Carleman estimates to solutions of direct and inverse problems for hyperbolic equations
(The University of Dodoma, 2015) Ngomaitala, Hussein Rajabu
A number of phenomena in modern science can be conveniently described in terms of problem for hyperbolic equation with Carleman estimates to the solution of inverse problem. The purpose of this study is to give a survey of the solution of the inverse problems for hyperbolic equation by Carleman estimates. We extend the results and prove the Carleman estimate focusing on an inverse problem for a simple hyperbolic equation. Also we derive the Lipschitz's stability by energy estimate; we obtain tomographic images by sent x-ray in different directions and measured at different places.
Numerical approximations to solutions of inverse problems for parabolic differential equations
(The University of Dodoma, 2015) Hamad, Hamad Makame
Present work is concerned with solved a coefficient inverse problem of one-dimensional parabolic equation by a higher-order compact finite difference method and we used this a fourth order efficient numerical method to calculate the function u (x; t) and the unknown coefficient a (t) in a parabolic partial differential equation. Also discussed the accuracy and efficiency of the fourth order finite difference formula compare with other finite difference methods such as FTCS explicit scheme, Crank-Necolson algorithm and Back ward time central space scheme. Results show that an excellent estimation on the unknown functions of the inverse problem can be obtained and the fourth order method developed in this work is well-balanced in stability, efficiency and accuracy.
Weights and ranks of causes of road accidents using Analytic Hierarchy Process (AHP) in Dodoma region
(The University of Dodoma, 2015) Omar, Said Hamad
The study of weights and ranks of causes of road accidents using Analytic Hierarchy Process (AHP) in Dodoma region has been conducted in order to provide a broad understanding to the seriousness of problem of Road Accidents in Tanzania. Since the problem of road accidents in Tanzania is highly increasing year after year, various preventive measures have been taken to reduce the rate of road accidents. Thus it is important to understand the actual causes which have high contribution to the road accidents. The main objective of this study is to propose weights and ranks of six selected causes with respect to five categories of motor vehicles associated with road traffic accidents in Tanzania. The five categories of motor vehicles are Lorries, Short Distance Passenger vehicles, Long Distance Passenger vehicles, Private Cars and Motorcycles while the selected causes are over speeding, reckless driving, Proper Use of Light during darkness, Adverse Road Conditions, Drivers‟ Behaviour and Drivers‟ Knowledge. Analytic Hierarchal procedure (AHP) is used as an analyzing tool. Through AHP questionnaire, data were collected from five experienced persons (experts) in road accident analysis. The experts rate the pair-wise comparison in measurement scale from one to five. The comparison scales were analyzed to compute the weights of road accident causes. The results of the study revealed that over speeding which means driving faster than limited speed is ranked as the highest cause in road accidents contribution with the weights 0.2905 followed by reckless driving (with weights 0.2812) while Adverse Road Condition is ranked as the lowest among the six selected road accident causes in this study.
On a global solution of the navier-stokes equations with internal body forces
(The University of Dodoma, 2015) Hamad, Salim Suleiman
The main objective of this study is on a global solution of the Navier-Stokes equations with internal body forces. The internal body forces play very important in both theory and application with Navier-Stokes equations. We discussed about the general solution for ordinary differential equations (ODES) and partial differential equations (PDES). Also they used the MAC model for incompressible flow. The study has been conducted in order to provide abroad understanding the existence of internal body forces with Navier-Stokes equations. The consideration of simple global solution the Navier-Stokes, equations with internal body forces is often possible.
A study on predator- prey systems with immigrant prey with and without harvesting
(The University of Dodoma, 2015) Kinyaga, Justine C.
The study of predator prey model with immigrant prey with and without harvesting has received great attention from both theoretical and mathematical biologists and has been studied intensively and extensively. Different literatures on interaction between species have been surveyed. In this document we establish sufficient stability criteria, criteria for the existence of periodic solution and Hopf bifurcations of a predator prey systems with immigrant prey without and with harvesting of predator. The ecological system in nature can be balanced by introducing an immigrant prey to ensure existence of both preys and predators. Harvesting of predator also can be used as a stabilizing factor as far as they depend on prey for their survival. The approach involves the use of software program (mat lab) in analyzing Equilibrium points, periodic solutions, Hopf bifurcations and its related theorems.
Overview numerical solutions for nonlinear partial differential equations with applications
(The University of Dodoma, 2015) Ndushi, Lwenge
This study is concerned with overview numerical solution for nonlinear partial differential equations. Since it is not easily to iterate the numerical scheme manually, C++ is used to encode the numerical scheme in order to find the numerical solution and Matlab is employed in drawing the figures. Chapter one consists of Introduction of Nonlinear Partial Differential equations, Literature Review, Classification of Partial Differential Equations, Examples of PDEs, Boundary Conditions, Taylor Expansion, Solution of a Partial Differential Equations, Truncation Error, Research Objective, Signification of the Study and Study Limitation. Chapter two contains Formulas of Finite Difference, Consistency, Stability and Convergence, Numerical scheme of Burgers' Equation, Sine Gordon Equation, Kortoweg-de Vries Equation, Gardner Equation and Fisher's Equation. Chapter three contains numerical and graphical results obtained by explicit scheme. In this chapter various examples of Burgers' equations, Sine Gordon Equation, Kortoweg-de Vries Equation, Gardner Equation and Fisher's Equation are discussed. Chapter four deals with Discussion, Conclusion and Recommendations.

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