Dinh Van Tiep, Tran Thi Hue

Cubature methods has been used and well developed to approximate integrals in high dimension for a long time. However, the number of functions evaluations increasing enormously large make a weak point for such methods. In that situation, adaptive cubature is often preferred choice because of a high efficiency and a low cost of calculation it brings back for the approximation problem. However, the data of the integrated regions and of values of the integrand must be continuous due to the theory of integration. It is infeasible to store in computer memory. To deal with this, the discretization of data for both of the region and the function values are used by constructing the net of the potential mesh points. This technique is acceptable since the result we want to extract is only an approximation within a requisite error. The paper aims to present that technique and some remarkable results.

]]>C. Nwaigwe, R. I. Ndu, A. Weli

We investigate the effects of moving channel wall, thermal radiation and variable-thermal conductivity on the flow of a non-Newtonian fluid in a porous channel. The effects on fluid temperature variations are also studied. By assuming that both the fluid viscosity and thermal conductivity are temperature-dependent, and incorporating viscous dissipation, uniform magnetic field and constant pressure gradient, the governing equations are presented. An implicit-explicit finite difference scheme is formulated and the numerical results are presented and discussed. The results show that near the moving wall, the transport of momentum, from the moving wall into the channel, is retarded by decrease in the fluid viscosity. While the opposite happens -velocity increases with decreasing viscosity- away from the moving wall where the pressure forces dominate the wall shearing forces.

]]>Kassahun Tesfaye Agzew

This research deals about annihilator ideal in almost semilattice(ASL) With 0 and annihilator preserving homomorphism. It is proved that the set of all annihilator ideals of an ASL L with 0 forms a complete Boolean algebra. Denition and examples of Ideal of Ring, Properties of ideal of Ring, Types of ideal of Ring, Partially ordered Set(poset), Lattice, Semilattice and Almost Semilattice concepts are also addressed. The second chapter deals about Annihilator ideal preserving homomorphism in almost semilattice. It contains two sections, that are Annihilator Ideal, and Annihilator Ideal preserving homomorphism and a sucient condition for homomorphism to be annilator preserving derived. Finally, it is proved that the homomorphic image and the inverse image of annihilator ideals are again annihilator ideals.

]]>Alfred Hugo, Eva Mwaseba Lusekelo, Raymond Kitengeso

This paper concentrates on the mathematical model for optimal control and cost-effectiveness analysis of tomato yellow leaf curl virus disease. The boundedness of the model has been analytically examined. The preferable optimal level of the intervention strategy to reduce the spreads and the cost of implementing control strategies were determined by introducing the time-dependent control. Pontryagin’s maximum principle was used to determine necessary conditions for the optimal control of the disease while numerical results obtained through forward-backward sweep method and fourth-order Runge-Kutta scheme using the forward solution of the state equations. The cost-effectiveness analysis results show that protective netting and removal of the infected plant is the most cost-effective strategy to combat the epidemic of tomato disease with limited resources. Therefore, TYLCV can be controlled if the farmers will effectively apply protective netting and remove the infected plants from the farm.

]]>Bosson-Amedenu Senyefia, James Hinson, Vivian Nimoh

This paper combined survey and survival studies with the aim of identifying risk factors for grade retention in Ghana. A sample of 120 basic school teachers comprising 60 male and 60 female across the 10 regions of Ghana responded to a four point likert scale with 15 items to measure perceived risk factors in the 120 sampled basic schools in Ghana. The distribution of the data did not approach the normal distribution so Mann Whitney’s U Test was employed in the analysis of the likert items. The findings of the survey research were validated with the findings of the cohort study. The second part of the study consisted of a cohort study of one private and one public school (selected through random sampling) from grade one to grade 9. Identified risk factors of grade retention in Ghana through the nonparametric analysis included children with learning difficulty (special needs), non- existing or non-operational counseling units, schools in rural community, abysmal average score, pupil in JHS level, pupil in Upper Primary level, Child’s low interest in school, Truancy and also the quest for Basic school authorities to obtain 100% pass rate in BECE results tends to increase their reluctance to register pupils who have poor academic record. The effect size for 15 Mann Whitney’s U Tests showed among others that 29.9% variability in the ranks was accounted for by “Truancy”. 78.2% variability in the ranks was accounted for by “Private School”. 37.5% variability in the ranks was accounted for by “Upper Primary status”. 16.9% variability in the ranks was accounted for by “Child interest in school”. 12.1% variability in the ranks was accounted for by “Desire of school to produce 100% passes in BECE”. The findings of the Cox PH Model validated grade level, truancy, children with learning difficulties, child’s low interest in school and low academic average score as risk predictors of grade retention in Ghana. Sex was not a significant predictor by Cox PH Model analysis. The study recommended for school authorities in Ghana to initiate interventions for pupils who show at least one of the risk factors identified in this research particularly for those pupils who show truancy which was the highest impact on grade retention, as shown by Cox PH Model analysis.

]]>Edward Obeng Amoako

SMEs (small medium-scale enterprises) occupy a central part of the economy in most developing countries all around the world. SMEs are noted as the bedrock of the emerging private sector in developing countries and government assistance is paramount to sustaining and growth for the sector’s contribution to the country’s economy (World Bank report, 2000). Despite effort to enhance performance of this sector very little or no attention is given to become business recovery consciousness when uncertain events occur in the line of business. Losses caused by events such as occupational hazards, theft and burglary, traffic and motor accidents, fire outbreaks and accidental damage to property and harm caused to lives as well as unknown events have slowed down the activities of the sector and in some instance have discontinued some businesses in the sector. The need to acquire insurance cover is cardinal to both the public, private sector and stakeholders, most importantly for the success and longevity of SMEs in the country. The basic motive of the research is to establish the predictors that affect SMEs in the Kumasi metropolis to patronise non-life insurance policies as a risk management tool.

]]>Edward Obeng Amoako

There have been a number of fire outbreak cases recorded in the KNUST area that has brought about loss of lives to inhabitants and loss of properties. Some routes within the district can be reconstructed into bitumen roads so that fire attackers can traverse through the district in order to prevent fire incidents. The main objective in this study is finding the minimum travel distances and shortest paths from the Knust Fire Station to all other towns in the district of Kumasi Metropolitan area in the Ashanti Region of Ghana. Shortest path algorithms of various variants have been discussed with examples in this study as well as review of abstracts of other related books and articles. The Floyd’s Algorithm has been explained in which it maximize the source node minus the destination node. It was found out that at each destination used in the objective function, the Floyd’s algorithm proceeds to obtain minimum distances to every other destination. The introductory part of the paper deals with the theory of searching for optimal routes in transport networks, including a description of each type of optimization tasks. The aim of the article is demonstration of Floyd algorithm application to find the minimal paths from each node to another in network graph - in our case the network represents traffic model of road network in the region of Knust.

]]>Md Shakhawat Hossain

The aim of this study is to discuss the weakness of the conventional way of presenting the relative intensities in multiplicative models. The identification problem in hazards models with multiple interactions is illustrated here. A proposed solution of this problem with a common baseline level rather than of using two pairs of baseline levels is demonstrated. A Bayesian approach with Markov Chain Monte Carlo (MCMC) algorithm is used to estimate the parameters of interest of a hazards model with multiple interactions. In this analysis MCMC chain has run for 12000 iterations then first 2000 are discarded as burn-in and retained 10000 for the posterior distribution. Various diagnostics like posterior autocorrelations, Gelman-Rubin diagnostic, Monte Carlo Standard Error (MCSE) are performed to check the Markov chain mixing and convergence to target posterior distribution. All these diagnostics are found statistically significant. The results are presented in a single table with common baseline level according to proposed solution. The major consequences of such presentation is that it is almost impossible to compare two separate tables entirely, while from a single table one can easily compare and interpret the results properly. Relative intensities are also computed from the posterior simulations in Bayesian analysis and presented in different tables and graphs.

]]>Salah H. Abid, Saad S. Mahmood, Yaseen A. Oraibi

The aim of this paper is to design a feed forward artificial neural network (Ann) to estimate two dimensional Tinkerbell dynamical map by selecting an appropriate network, transfer function and node weights. The proposed network side by side with using Fast Fourier Transform (FFT) as transfer function is used. For different cases of the system, chaotic and noisy, the experimental results of proposed algorithm will compared empirically, by means of the mean square error (MSE) with the results of the same network but with traditional transfer functions, Logsig and Tansig. The performance of proposed algorithm is best from others in all cases from Both sides, speed and accuracy.

]]>Simon Razmadze

The paper presented considers the ordering method of outcome set for multi-stage testing (MST) of 1-2-4 model. The ordering method of outcome set is used for the estimation of results of computerized adaptive testing (CAT). This method is not tied to a specific testing procedure. Acknowledgment of this is its usage for the 1-2-4 model, which is described in the paper. To sort the set of testing outcomes the function-criteria described in the initial article are used here and a comparative analysis of obtained results is performed. The ordered outcome set is estimated by a hundred-point system according to the normal distribution.

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