2022-07-05T06:07:00Z https://academicjournals.org/oai-pmh/handler
oai:academicjournals.org:AJMCSR:6BD9FD83445 2008-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2008
Thermal modeling and performance evaluation of arch shape greenhouse for nursery raising S. H. Sengar and S. Kothari Full Length Research Paper This paper presents mathematical model for predicting thermal environment inside the arch shape greenhouse. Predicted thermal environment inside the greenhouse helped to select the crop nursery for growing inside the greenhouse. Actual thermal environment inside the greenhouse compared with predicted thermal environment. Experimental and predicted values of greenhouse temperature were almost same with variation of 2 to 3oC. Key words: Arch shape greenhouse, mathematical model. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/6BD9FD83445 http://dx.doi.org/10.5897/AJMCSR.9000126 en Copyright © 2008 S. H. Sengar and S. Kothari
oai:academicjournals.org:AJMCSR:A6B05A93475 2008-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2008
Dual factor routing protocol for mobile ad hoc networks R. Praveen Sam, P. Chandrasekhar Reddy and B. Stephen Charles Full Length Research Paper Mobile ad hoc networking works properly only if the participating nodes cooperate in routing and forwarding. In this work, the question of how to enable a system to operate despite the presence of misbehavior node is considered. Node misbehavior due to selfish or malicious reasons or faulty nodes can significantly degrade the performance of mobile ad hoc networks. A new protocol called DUAL Factor is proposed to manage with misbehavior nodes. It considers two factors, Direct Factor and Distributed Factor, called DUAL Factor. The DUAL Factor protocol works as an extension to a reactive source-routing protocol for mobile ad-hoc networks. The performance analysis of DUAL Factor is done by comparing it to the standard DSR protocol. It shows that a network with DUAL Factor and up to 60% of misbehaving nodes behaves almost same as a caring network, in sharp contrast to a standard DSR network. All simulations have been implemented and performed in ASIM Simulator. Key words: MANET, DSR routing protocol, DUAL factor routing protocol, ASIM simulator. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/A6B05A93475 http://dx.doi.org/10.5897/AJMCSR.9000060 en Copyright © 2008 R. Praveen Sam, P. Chandrasekhar Reddy and B. Stephen Charles
oai:academicjournals.org:AJMCSR:25DE4EE3487 2008-10-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2008
Multi agent system for resource allocation and monitoring M. Syamala Devi and Manish Arora Review The objective of this paper is to present a model that uses Multi Agent Technology to assist Fund Allocating Agencies (FAA) to allocate limited funds to most deserving among competing organizations called Fund Seekers (FS) and monitoring the utilization of allocated funds. These funds are given to execute their projects in Research and Development or to impart quality education. In India, the beneficiaries of this system are likely to be those organizations that allocate funds like University Grant Commission (UGC), Department of Science and Technology, Department of Information Technology and FS that avail funds, could be any university or college. To manage decision-making in such a distributed environment, a Multi Agent System (MAS) for resource allocation was designed. Five agents were identified. One agent, called Coordinator Agent has been designed to perform task of helping FS to find sources of funds available depending on nature of projects, second agent called Fund Allocating Agency Agent has been designed to provide the funds, third agent called Fund Allocator Agent has been designed to allocate funds, fourth agent called Fund Seeker has been designed to avail the funds and lastly Monitor Agent has been designed to monitor the progress of utilization of funds. MAS, methodology are used to model the problem. It consists of number of agents that interact with one another. An Agent is an autonomous entity that performs a given task using information gathered from its environment to act in a suitable manner so as to complete the task successfully. This paper describes the steps carried out to model the problem. To implement the model, physical computing and network infrastructure are required. Key words: Agents, multi agent system, funds allocation, decision making, distributed environment. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/25DE4EE3487 http://dx.doi.org/10.5897/AJMCSR.9000084 en Copyright © 2008 M. Syamala Devi and Manish Arora
oai:academicjournals.org:AJMCSR:0AF15253495 2008-10-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2008
Conjugate gradient method for non-positive definite matrix operator Omolehin J.O., Abdulrahman M.K.A., Rauf K.and Udoh P.J. Full Length Research Paper The conjugate Gradient Method relies on symmetric positive definite property of a matrix operator. In this work, we investigate and establish the case of non-positive symmetric matrix operator using various forms of conversions and transformations on the operator. Key words: Hilbert Space, Positive Symmetric Matrix, Quadratic Functional, Conjugate, Gradient Method. Academic Journals 2008 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/0AF15253495 http://dx.doi.org/10.5897/AJMCSR.9000055 en Copyright © 2008 Omolehin J.O., Abdulrahman M.K.A., Rauf K.and Udoh P.J.
oai:academicjournals.org:AJMCSR:CA194F13518 2009-02-28T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
An empirical optimal portfolio selection model A. C. Okoroafor and B. O. Osu Full Length Research Paper We consider risk arising from changes in the prices of financial assets. We propose a risk measure based on asymptotic power law behaviour for optimal portfolio selection in a single period. We apply this measure to compute explicitly the optimal portfolio when the underlying security prices follow a Weibull distribution. An illustrative example is given. Key words: Asymptotic power law, asset price change, Weibull distribution, portfolio selection, mathematics subject classification: 91B60, 91B26 Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/CA194F13518 http://dx.doi.org/10.5897/AJMCSR.9000040 en Copyright © 2009 A. C. Okoroafor and B. O. Osu
oai:academicjournals.org:AJMCSR:BDEF0BD3524 2009-02-28T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Reliability equivalence factors for some systems with mixture weibull failure rates A. Mustafa Full Length Research Paper In this article, the failure rates of the system#39;s components are functions of time t. We study two cases (i) the mixture of two stages of life time distribution with weibull failure rates, (ii) the mixture of two stages failure rates with weibull distribution. The reliability equivalence factors of some systems with identical components are obtained. Two different methods are used to improve the given systems. Numerical examples are presented to interpret how one can utilize the obtained results. Some special cases are obtained from our results. Key word: Weibull failure rate distribution, Rayleigh distribution, exponential distribution, mixture distributions, mixture failure rates, hot duplication, reduction method, reliability equivalence factors Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/BDEF0BD3524 http://dx.doi.org/10.5897/AJMCSR.9000107 en Copyright © 2009 A. Mustafa
oai:academicjournals.org:AJMCSR:4AE95703536 2009-03-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Mathematical model of ecological disturbances in the oil rich Niger Delta region of Nigeria O. O. Ugbebor and P .O. K. Aiyelo Full Length Research Paper An important class of interactions between biological species is the stability. We investigate the ecological, biological and economical impacts of petroleum exploration on the Niger Delta region of Southern Nigeria. A modified reaction-diffusion model describing the spread of the predators into the prey populations is adopted to establish the interaction between the parties involved. An attempt was made to explore dispersion and patchiness of the residents resulting from these issues. Evidence from this study showed that continual invasions of the prey species by the predator species could lead to extinction of the former in the long run. Strategies are suggested on how to ensure peace and coexistence in the region. Key words: Reaction-diffusion, dispersion, patchiness, stability. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/4AE95703536 http://dx.doi.org/10.5897/AJMCSR.9000076 en Copyright © 2009 O. O. Ugbebor and P .O. K. Aiyelo
oai:academicjournals.org:AJMCSR:F8015A13550 2009-03-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
On two-sample test for detecting differences in the IFR property of life distributions Parameshwar V. Pandit and Nagaraj V. Gudaganavar Full Length Research Paper A test proposed for testing whether one distribution is more Increasing Failure Rate (IFR) than another, based on a measure of IFR is presented in this paper. The asymptotic normality of the proposed test statistic was also established. The asymptotic null variance from the data was estimated since the variance depends on the unknown distribution. The Pitman asymptotic efficacies of the proposed test statistic are computed for various alternative IFR distributions. Key words: Two-sample test, IFR, Pitman efficacy. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/F8015A13550 http://dx.doi.org/10.5897/AJMCSR.9000094 en Copyright © 2009 Parameshwar V. Pandit and Nagaraj V. Gudaganavar
oai:academicjournals.org:AJMCSR:130A5DB3567 2009-04-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Profile of conjugate gradient method algorithm on the performance appraisal for a fuzzy system J. O. Omolehin, A. O. Enikuomehin, R. G. Jimoh and K. Rauf Full Length Research Paper The formalism of Minkwoskyrsquo;s inequality in Omolehin (2007a) is used in this work fundamentally to generate the fuzzy model for system performance appraisal in two public examinations in Nigeria. The Conjugate Gradient Method Algorithm (CGM) is employed to evaluate the validity of our results from the large system fuzzy performance. Results showed that our methods are credible and reliable. Key words: Minkowskirsquo;s inequality, conjugate, gradient method, fuzzy system, operator, quadratic cost functional. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/130A5DB3567 http://dx.doi.org/10.5897/AJMCSR.9000102 en Copyright © 2009 J. O. Omolehin, A. O. Enikuomehin, R. G. Jimoh and K. Rauf
oai:academicjournals.org:AJMCSR:7808B783583 2009-04-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Development of a mathematical model for error propagation in engineering calculations involving many variables function S. K. Fasogbon Full Length Research Paper In this research, a mathematical model for error propagations in many variables functions had been developed. The development employs both Taylor theorem and binomial coefficient of expansion. Verification of the models were done through computer simulation by comparing the results of the model with the actual difference between the result given by the function in question, when computed with lsquo;error variablersquo; and the same function when computed with lsquo;error free variablersquo;. The results given by the model proposed, gave good results for error propagation that were not significantly different from that obtained from the actual difference between the results of the error variable functions and lsquo;error free variablersquo; functions. Key words: Mathematical model, error propagation, many variables function, engineering calculation. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/7808B783583 http://dx.doi.org/10.5897/AJMCSR.9000059 en Copyright © 2009 S. K. Fasogbon
oai:academicjournals.org:AJMCSR:C604F973610 2009-04-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Some affine connexions in a generalized structure manifold R. P. Singh and S. D. Singh Full Length Research Paper In this paper we have studied some affine connexions in a generalised structure manifold. Certain theorems are have also been proved, which are of great geometrical importance. Key words: Cinfin;-manifold, generalised structure, generalised metric structure, F- structure, pi; structure, AMS Subject Classification Number: 53 Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/C604F973610 http://dx.doi.org/10.5897/AJMCSR.9000113 en Copyright © 2009 R. P. Singh and S. D. Singh
oai:academicjournals.org:AJMCSR:7475EB43678 2009-04-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
A simple experimental verification for Einstein’s variance of mass with velocity equation M. Sivasubramanian and S. Kalimuthu Short Communication Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/7475EB43678 http://dx.doi.org/10.5897/AJMCSR.9000036 en Copyright © 2009 M. Sivasubramanian and S. Kalimuthu
oai:academicjournals.org:AJMCSR:AFC01693706 2009-05-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
A collocation multistep method for integrating ordinary differential equations on manifolds J. O. Fatokun and I. K. O. Ajibola Full Length Research Paper This paper concerns a family of generalized collocation multistep methods that evolves the numerical solution of ordinary differential equations on configuration spaces formulated as homogeneous manifolds. Collocating the general linear method at x = xx+k for k = 0,1,hellip;.s, , we obtain the discrete scheme which can be adapted to homogeneous spaces. Varying the values ofk in the collocation process, the standard Munthe-Kass (k = 1) and the linear multistep methods (k = s) are recovered. Any classical multistep methods may be employed as an invariant method and the order of the invariant method is as high as in the classical setting. In this paper an implicit algorithm was formulated and two approaches presented for its implementation. Key words: Collocation, multistep methods, homogeneous manifolds, implicit methods, invariant methods, differential equations on manifolds, geometric integration. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/AFC01693706 http://dx.doi.org/10.5897/AJMCSR.9000026 en Copyright © 2009 J. O. Fatokun and I. K. O. Ajibola
oai:academicjournals.org:AJMCSR:0CC63383714 2009-05-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
When does the pooled variance t-test fail? Teh Sin Yin and Abdul Rahman Othman Full Length Research Paper The pooled variance t-tests used prominently for comparing means between two groups is usually restricted with the assumptions of normality and homogeneity of variances. However, the violation of the assumptions happens in many real world data. In this study, the conditions where the pooled variance t-test would fail were investigated. The performance of the t-test was evaluated under different conditions. They were sample sizes, type of distributions (normal or non-normal), and unequal group variances. The Type I error rates and power of the pooled variance t-tests for different designs were obtained and compared. The results showed that the test failed dramatically when the group sample sizes were small and unequal with slight departure from homogeneity of variances. Key words: Pooled variance, power, t-test, type 1 error. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/0CC63383714 http://dx.doi.org/10.5897/AJMCSR.9000132 en Copyright © 2009 Teh Sin Yin and Abdul Rahman Othman
oai:academicjournals.org:AJMCSR:A57C6493723 2009-05-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Application of variational iteration method to coupled system of nonlinear partial differential physical equations Abdoul R. Ghotbi, A. Barari, M. Omidvar and D. D. Ganji Full Length Research Paper In this article 2 examples of the coupled system of nonlinear partial differential physical equations including diffusion-reaction equation have been investigated by means of variational iteration method which is a new numerical method for solving these types of equations. The results are presented finally in comparison with the exact solution, which show a good agreement and consistency with the exact solution and introduce this method as a powerful and applicable one in this field. Key words: Variational iteration method, physical system of nonlinear differential equation, diffusion-reaction equation. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/A57C6493723 http://dx.doi.org/10.5897/AJMCSR.9000043 en Copyright © 2009 Abdoul R. Ghotbi, A. Barari, M. Omidvar and D. D. Ganji
oai:academicjournals.org:AJMCSR:4C82B454303 2009-05-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
A class of collocation methods for general second order ordinary differential equations Y. A. Yahaya and A. M. Badmus Full Length Research Paper In this paper, self starting hybrid block method of order (4,3,3)T is proposed for the solution of general second order initial value problem of the form Yrdquo; = f (x, y, yrsquo;) directly without reducing it to first systems of odes. The continuous formation of the integrator enable us to differentiate and evaluate at some grids and off-grid points to take care of yrsquo; in the method. The schemes compare favorably with optimal order four (Fatunla Based) proposed in Yahaya (2004). There is anticipated speed up of computation as a result of admissible parallelism across the method. Key words: General second order, initial value problems, parallel/block method, hybrid, self starting. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/4C82B454303 http://dx.doi.org/10.5897/AJMCSR.9000024 en Copyright © 2009 Y. A. Yahaya and A. M. Badmus
oai:academicjournals.org:AJMCSR:18A03F44309 2009-05-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Pre A*-Algebra as a Poset J. Venkateswara Rao and K. Srinivasa Rao Full Length Research Paper This paper is a study on algebraic structure of pre A*- algebra. We define center of a pre A*-algebra, B(A) = {x Icirc; A/ x Uacute; x0/0 1} and prove that B(A) is a Boolean algebra. We define ordering relation on pre A*- algebra A by x le; y if yUgrave;x = xUgrave;y = x and prove that le; is a partial ordering on A and also find necessary conditions for the poset (A, pound;) to become a lattice. We prove that for each xIcirc;A, Ax = {s Icirc; A / s pound; x} is a pre A*-algebra under the induced operations, Ax is isomorphic to a quotient algebra of A. that is, A/q @ A, where qx = {(s,t) Icirc; A acute; A / x Ugrave; s = x Ugrave; t}. Key words: Pre A*-Algebra, poset, algebraic structure, Boolean algebra. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/18A03F44309 http://dx.doi.org/10.5897/AJMCSR.9000100 en Copyright © 2009 J. Venkateswara Rao and K. Srinivasa Rao
oai:academicjournals.org:AJMCSR:FBF425F4318 2009-06-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Robustness of the maximum likelihood estimation procedure in factor analysis Nwabueze, Joy Chioma, Onyeagu, Sidney I. and Ikpegbu Onyedikachi Full Length Research Paper Random variables generated from five distributions were used to represent the common and specific factors in factor analysis in order to determine the robustness of the maximum likelihood estimation procedure. Five response variables were chosen for this study each with two factors. The chosen variables were transformed into linear combinations of an underlying set of hypothesized or unobserved components (factors). The result revealed that the estimates of the variance for the first factor were found to be almost the same and closely related to each other in all the distributions considered. The Chi-Square test conducted concluded that maximum likelihood method of estimation is robust in factor analysis. Key words: Maximum likelihood, factor analysis, robustness, distributions, Random variables,Chi-Square test. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/FBF425F4318 http://dx.doi.org/10.5897/AJMCSR.9000108 en Copyright © 2009 Nwabueze, Joy Chioma, Onyeagu, Sidney I. and Ikpegbu Onyedikachi
oai:academicjournals.org:AJMCSR:CBC5A274338 2009-06-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Statistical analysis of dependence structure of improved cassava varieties in Nigeria Nwabueze Joy Chioma Full Length Research Paper Multivariate methods were used to analyze a set of data on the proximate compositions of fufuflours processed from 43 different cassava mosaic disease (CMD) resistant varieties from National Root Crop Research Institute (NRCRT) Umudike Nigeria. The factor analysis reveals that three factors accounted for 77.8% of the total variables in the data. Factor 1 has eigenvalue of 3.082, factor 2 has an eigen 1.257 and factor 3 has an eigenvalue of 1.005. The scree plot of the data also showed that 3 factors were retained in the study. Key words: Multivariate statistics, factor analysis, eigenvalue, scree plot, cassava varieties. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/CBC5A274338 http://dx.doi.org/10.5897/AJMCSR.9000121 en Copyright © 2009 Nwabueze Joy Chioma
oai:academicjournals.org:AJMCSR:1955D3F4357 2009-07-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Graphics to fuzzy elements in appraisal of an in-house software based on inter-failure data analysis J. O. Omolehin, K. Rauf, R. G. Jimoh and O. C. Abikoye Full Length Research Paper The performance of any software can be measured, approximately, by three parameters; Reliability, Availability and Maintainability. They provide information about the robustness of the software under consideration. In this work, a software is developed to computerize University of Ilorin studentrsquo;s results and is designated as an IN-HOUSE Software. The formalism of fuzzy logic is used to investigate its performance. Our results show that the metrics for performance testing by Pfleeger (1997) perform better when the raw data is refined (fuzzified). Key words: Software, graphics, fuzzy, decision table, center of area. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/1955D3F4357 http://dx.doi.org/10.5897/AJMCSR.9000070 en Copyright © 2009 J. O. Omolehin, K. Rauf, R. G. Jimoh and O. C. Abikoye
oai:academicjournals.org:AJMCSR:8A424474364 2009-07-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Stability analysis of stochastic model of stock market price B. O. Osu, A. C.Okoroafor and C .Olunkwa Full Length Research Paper A stability analysis of stochastic model of price change at the floor of a stock market is considered. Precise conditions are obtained which determine the equilibrium price and growth rate of the stock shares in a particular case. In general, stability in a numerical procedure for the Black-Scholersquo;s partial differential equation is established. An illustrative example is provided. Key words: Stability analysis, stochastic model, stock price changes, Black-Scholersquo;s PDE, mathematics subject classification: 91B26, D91, 91B60. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/8A424474364 http://dx.doi.org/10.5897/AJMCSR.9000120 en Copyright © 2009 B. O. Osu, A. C.Okoroafor and C .Olunkwa
oai:academicjournals.org:AJMCSR:01B5CE54389 2009-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Applications of soft computing techniques in materials engineering: A review Odetunji A. Odejobi and Lasisi E. Umoru Review Within the last two decades, a substantial amount of research efforts has been directed at the application of Soft Computing (SC) techniques in engineering. This paper provides a systematic review of the literature emanating from these efforts with particular focus on materials engineering. The primary aim is to provide background information, motivation for applications and an exposition to the methodologies employed in the development of soft computing technologies in engineering. Our review shows that all the works on the application of SC to materials engineering have reported excellent, good, positive or at least encouraging results. In our opinion, the lack of negative results might be due to the simplification of materials engineering problems to manageable and predictable situations. We draw particular attention to the strengths and weaknesses of soft computing techniques in the context of materials engineering applications. Our appraisal of the literature suggests that the interface between materials engineering and intelligent systems engineering techniques, such as soft computing, is still blur. The need to formalise the computational and intelligent systems engineering methodology used in materials engineering, therefore, arises. We also provide a brief exposition to our on-going efforts in this direction. Although our study focuses on materials engineering in particular, we think that our findings applies to other areas of engineering as well. Key words: Composite materials, fuzzy logic, soft computing, intelligent systems engineering,formal methods. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/01B5CE54389 http://dx.doi.org/10.5897/AJMCSR.9000044 en Copyright © 2009 Odetunji A. Odejobi and Lasisi E. Umoru
oai:academicjournals.org:AJMCSR:200843C4396 2009-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
On sandwich theorems of analytic functions involving Noor integral operator R. W. Ibrahim and M. Darus Full Length Research Paper In this paper, we introduce sufficient conditions for subordination and superordination for subclass of analytic functions containing Noor integral operator. On the other hand, we prove the subordination and superordination results by some theorem studies and proofs. There are also obtained a sandwich results by different ways. Key words: Noor integral operator, subordination, superordination. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/200843C4396 http://dx.doi.org/10.5897/AJMCSR.9000093 en Copyright © 2009 R. W. Ibrahim and M. Darus
oai:academicjournals.org:AJMCSR:24437824406 2009-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
M|G|∞ queue system parameters for a particular collection of service time distributions Ferreira, Manuel Alberto M. and Andrade, M. Full Length Research Paper The problems that arise in the computation of the moments of a particular collection of service time distributions, for which the M|G|infin; busy period and busy cycle become very easy to study, are presented in this paper. It is shown how to overcome them. The busy cycle renewal function, the ldquo;peakrdquo; and the ldquo;modified peakrdquo; for the M|G|infin; busy period and busy cycle in the case of those service time distributions are also computed. Key words: Probability distributions, M|G|infin;, busy period, busy cycle. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/24437824406 http://dx.doi.org/10.5897/AJMCSR.9000085 en Copyright © 2009 Ferreira, Manuel Alberto M. and Andrade, M.
oai:academicjournals.org:AJMCSR:E7BFE5B4417 2009-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Slip formulation for numerical simulations of jumping paratroopers Victor Udoewa Full Length Research Paper The aim is to develop computational techniques for studying aerodynamic interactions between multiple objects when an object exits and separates from an aircraft. The object could be a paratrooper jumping out of a transport aircraft or a package of emergency aid dropped from a cargo plane. In all these cases, the computational challenge is to predict the dynamic behavior and path of the object, so that the separation process is safe and effective. This is a very complex problem because it has an unsteady, 3D nature and requires the solution of complex equations that govern the fluid dynamics of the object and the aircraft together, with their relative positions changing in time. In advection-dominated flows, the numerical boundary layer is excessively thick and not physically real. Computational methods used to solve such problems much address this as a numerically thick boundary layer can artificially affect the dynamics and trajectory of moving objects. In the presented research, numerically thick boundary layers were reduced for 3D flows specifically focusing on paratrooper-aircraft separation. Slip formulations were found to provide an excellent numerical approximation of a thin boundary layer for this application. A real paratrooper trajectory was numerically simulated. Key words: Mesh resolution, boundary layer, mesh generation, boundary layer resolution, boundary layer elements, slip conditions, Navier-stokes equation, incompressible flow. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/E7BFE5B4417 http://dx.doi.org/10.5897/AJMCSR.9000111 en Copyright © 2009 Victor Udoewa
oai:academicjournals.org:AJMCSR:BDD7B234422 2009-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Modeling laminar flow between a fixed impermeable disk and a porous rotating disk D. P. Kavenuke, E. Massawe and O. D. Makinde Full Length Research Paper We formulate a mathematical model that governs operations of many engineering systems particularly the ceiling fan to explain the fluid flow between the fixed impermeable and the porous rotating disks. The model is based on the continuity and the Navier-Stokes equations which are reduced into a set of coupled ordinary differential equations through transformation by similarity variables. The coupled ordinary differential equations are solved using perturbation techniques and the series solution obtained is improved by Pateacute;rsquo;s approximation. Our results meet the supposition that, with laminar flow regime, suction increases with increasing speed of rotation of the rotating porous disk and these are shown on the graphical representations. Key words: Impermeable disk, laminar flow, porous rotating disk, shear stress, Padeacute; approximation. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/BDD7B234422 http://dx.doi.org/10.5897/AJMCSR.9000082 en Copyright © 2009 D. P. Kavenuke, E. Massawe and O. D. Makinde
oai:academicjournals.org:AJMCSR:8FB1C0B4543 2009-09-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Adaptation of the preemptive handoff scheme in an integrated mobile communication environment Chiranjeev Kumar and Rajeev Tripathi Full Length Research Paper A new preemptive handoff scheme in integrated mobile communication environment is presented in this paper. The preemptive handoff schemes have worked in such a way that data types of lesser priority have been preemptive in an ad-hoc fashion. In the proposed scheme, the cell is divided into two regions, the usable area and the handoff region. The right of preemption has been given to incoming handoff real-time (voice) calls. The incoming handoff calls can only preempt ongoing calls present in the handoff region. Calls present in the usable area are not touched. Thus, a degree of protection is offered to the ongoing calls in the handoff region, whatever type of calls they may be. Key words: Preemptive handoff, non-preemptive handoff, real-time traffic, non-real time traffic, blocking probability. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/8FB1C0B4543 http://dx.doi.org/10.5897/AJMCSR.9000038 en Copyright © 2009 Chiranjeev Kumar and Rajeev Tripathi
oai:academicjournals.org:AJMCSR:DF0B5E14513 2009-09-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Causal relationship between gross domestic product and personal consumption expenditure of Nigeria Nwabueze Joy Chioma Full Length Research Paper This study employed regression analysis to investigate the casual relationship between gross domestic product and personal consumption expenditure of Nigeria using data from 1994 - 2007. A non insignificant value of 0.0514 was obtained as a slope coefficient indicating that an increase in gross domestic product has no significant effect on the personal consumption expenditure of Nigeria. This was further evidenced by the value of the coefficient of determination which was only 0.035 implying that the gross domestic product only explained about 3.5% of the personal consumption expenditure of Nigeria. Key words: Causal relationship, coefficient of determination, gross domestic product, personal consumption expenditure, investment, government spending, consumer price index, implicit price deflator. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/DF0B5E14513 http://dx.doi.org/10.5897/AJMCSR.9000048 en Copyright © 2009 Nwabueze Joy Chioma
oai:academicjournals.org:AJMCSR:A5E3EF14475 2009-09-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
A dimension result for polar sets of Brownian path in n-spaces A. C. Okoroafor and P. U. Uzoma Full Length Research Paper Let T(x,r) denote the occupation measure of the ball of radius r centered at x for Brownian motion {Xr},0 lt; t lt; 1 in Rn , n gt; 3. We consider the set and show that for a = 0,h(r) = r2 (logr)lambda;, lambda; gt; 1. Moreover, E0 n Ea = oslash; for a gt; 0. We deduce that the Hausdorff dimension of E0 is 2 for n gt; 3 Key words: Brownian motion, Hausdorff dimension, multifractal analysis, polar sets, occupation measure. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/A5E3EF14475 http://dx.doi.org/10.5897/AJMCSR.9000029 en Copyright © 2009 A. C. Okoroafor and P. U. Uzoma
oai:academicjournals.org:AJMCSR:97AE1094581 2009-10-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Enhanced data mining analysis in higher educational system using rough set theory P. Ramasubramanian, K. Iyakutti and P. Thangavelu Review One of the biggest challenges that higher education faces today is predicting the behavior of students. Institutions would like to know, something about the performances of the students group wise. Behrouzndash;Minaei-Bidgoli (2004) investigated a web based educational system using data mining techniques. He proposed a problem to investigate the performances of the students when the large data base of Students information system (SIS) is given. Generally studentsrsquo; problems will be classified into different patterns based on the level of students like normal, average and below average. In this paper we attempt to analyze SIS database using rough set theory to predict the future of students. Key words: Data mining, knowledge discovery, rough set, lower approximation and upper approximation, characteristic sets, missing attribute values. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/97AE1094581 http://dx.doi.org/10.5897/AJMCSR.9000061 en Copyright © 2009 P. Ramasubramanian, K. Iyakutti and P. Thangavelu
oai:academicjournals.org:AJMCSR:D69BD914640 2009-10-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Cluster analysis of improved cassava varieties cultivated at Onne, Nigeria by the international institute of tropical agriculture Nwabueze, Joy Chioma Full Length Research Paper Secondary data on proximate composition of ldquo;fufurdquo; flour taken from forty three cassava mosaic disease (CMD) resistant varieties were used for this work. Agglomerative hierarchical cluster analysis was performed on the squared Euclidean distance matrix. The distance coefficients generated between the forty three CMD resistant varieties ranged from 0.000 to 89.120. Six (6) distinct groups were identified at 0.97 coefficients. A dendrogram of the data indicated that cases with low distances are close together with a line linking them. It was observed that the line was a short distance from the left of the dendrogram indicating that they were agglomerated in a cluster at a low distance coefficient. This indicated likeness. The implication of this to the farmer and indeed to the nutritionist is that a variety can be selected from each of the 6 cluster groups for cultivation with the objective of achieving the same nutritional differences in terms of proximate composition without having to examine all the forty three varieties. Key words: Cluster, agglomerative hierarchical cluster, squared euclidean distance, cassava ldquo;fufurdquo;, CMD-resistant varieties, clustering algorithms. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/D69BD914640 http://dx.doi.org/10.5897/AJMCSR.9000050 en Copyright © 2009 Nwabueze, Joy Chioma
oai:academicjournals.org:AJMCSR:9511BAC4609 2009-10-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Comparison of electron-plasmon scattering effect on low-field electron mobility in ZnO and SiC H. Arabshahi and M. Rezaee Rokn-Abadi Full Length Research Paper Iterative technique is used to solve Boltzmann transport equation for calculating temperature and doping dependencies of electron mobility in ZnO and SiC materials. The two-mode nature of the polar optic phonons is considered jointly with deformation potential acoustic, piezoelectric, ionized impurity and electron-plasmon scattering. Band non-parabolicity, admixture of p functions, arbitrary degeneracy of the electron distribution, and the screening effects of free carriers on the scattering probabilities are incorporated. It is shown that electron-plasmon scattering affects substantially the low-field electron mobility in bulk ZnO and SiC. It is found that the electron mobility decreases monotonically as the temperature increases from 300 - 600 K. The low temperature value of electron mobility increases significantly with increasing doping concentration. The iterative results are in fair agreement with other recent calculations obtained using the relaxation-time approximation and experimental methods. Key words: Electron-plasmon, relaxation-time, Boltzmann equation, non-parabolicity, degeneracy. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/9511BAC4609 http://dx.doi.org/10.5897/AJMCSR.9000051 en Copyright © 2009 H. Arabshahi and M. Rezaee Rokn-Abadi
oai:academicjournals.org:AJMCSR:24E49D84678 2009-11-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
A catastrophic-cum-restorative queuing model with correlated input for the cell traffic generated by new broadband services Rakesh Kumar Full Length Research Paper A Catastrophic-cum-Restorative Queuing Model has been developed for the cell traffic generated by New Broadband services. Transient analysis of the queuing model has been carried out. Some particular cases of the model have been derived and discussed. Key words: Catastrophes, correlation, broadband services, restoration. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/24E49D84678 http://dx.doi.org/10.5897/AJMCSR.9000023 en Copyright © 2009 Rakesh Kumar
oai:academicjournals.org:AJMCSR:B8EC8FE4672 2009-11-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Relative efficiency of non parametric error rate estimators in multi-group linear discriminant analysis Romain Lucas Glegrave;legrave; Kakaiuml;, Dieter Pelz and Rudy Palm Full Length Research Paper A Monte Carlo study was achieved to assess the relative efficiency of ten non parametric error rate estimators in 2, 3 and 5-group linear discriminant analysis. The simulation design took into account the number rho; of variables (4, 6, 10, 18) together wit the size sample n so that: n/rho; = 1.5, 2.5 and 5. Three values of the overlap, e of the populations were considered (e = 0.05, e = 0.1, e = 0.15) and their common distribution was Normal, Chi-square with 12, 8, and 4 df; the heteroscedasticity degree, was measured by the value of the power function, 1-beta; of the homoscedasticity test related to (1-beta; = 0.05, 1-beta;=0.4, 1-beta; =0.6, 1-beta; =0.8). For each combination of these factors, the actual error rate was empirically computed as well as the ten estimators. The efficiency parameter of the estimators was their relative error, bias and efficiency with regard to the actual error rate, empirically computed. The results showed the overall best performance e632 estimator. On the contrary, e0, erho;rho;, erho;rho;CV and eA recorded the lowest performance in terms of mean relative error and mean relative bias. The ranks of the estimators were not influenced by the number of groups but for high values of the later, the mean relative bias of the estimators tend to zero. Key words: Error rate, estimation, efficiency, multi-group, linear rule, simulation. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/B8EC8FE4672 http://dx.doi.org/10.5897/AJMCSR.9000105 en Copyright © 2009 Romain Lucas Glegrave;legrave; Kakaiuml;, Dieter Pelz and Rudy Palm
oai:academicjournals.org:AJMCSR:EFC065A4669 2009-11-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Visualizing the behaviour of reinforced concrete beam structure under various types of loadings L. O. Yusuf, O. Folorunso, A. T. Akinwale and A. I. Adejumobi Full Length Research Paper This paper describes an approach to visualizing the detection of failure in Reinforced Concrete Beam Structure under various types of loadings. Several Reinforced Concrete Design (RCD) tools have been developed to support RCD, but there is little evidence that these solutions address the needs of the users. We studied RCD analystsrsquo; daily activities in order to understand their routine work practices and the need for designing RCD tools. Our approach is based on the principle of information visualization which has been applied in related fields. The Model-View-Controller (MVC) architecture is used to alleviate the black box syndrome associated with the study of algorithm behaviour for RCD for Beams. We propose a Visualization ldquo;exploratoryrdquo; tool that assists the RCD designer in understanding the actual behaviour of the RCD Beam algorithms of choice and also in evaluating the performance quality of the algorithm. We demonstrate the feasibility of our approach using Simply Supported Reinforced Concrete Beam Structure (SSRCBS). We review Structural Analysis of Simply Supported Beam; our choice of design is governed by British Standard Code of Practice. VisRCD Beam Interface is created as our input visualization environment while borrowing and enhancing AutoCAD Interface as the output visualization environment. The analysis led to the development of a process model for SSRCBS work and related visualization needs. Our hypothesis testing reveals that RCD analyst will perform task and achieve acceptable results in less than 6frac12; min. The tool provides great benefit to the user by making their observations and judgement count. Key words: Visualization, AutoCAD objects imported to VB.Net, state-of-the-art visualization, SSRCBS, VBA. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/EFC065A4669 http://dx.doi.org/10.5897/AJMCSR.9000131 en Copyright © 2009 L. O. Yusuf, O. Folorunso, A. T. Akinwale and A. I. Adejumobi
oai:academicjournals.org:AJMCSR:283F7534742 2009-12-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Curve concentration for a singularly perturbed Neumann problem in three dimensional domain Jun Yang Full Length Research Paper In this paper we consider the following problem where is a bounded domain in with smooth boundary, is a small parameter, denotes the outward normal of and . Let be a straight line intersecting with at exactly two points. We will prove the existence of a solution possessing curve concentrating set near , exponentially small in at any positive distance from the concentrating set, provided is small and away from certain critical numbers. Key Words: Curve concentration, singular perturbation, neumann problems, spike layer. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/283F7534742 http://dx.doi.org/10.5897/AJMCSR.9000056 en Copyright © 2009 Jun Yang
oai:academicjournals.org:AJMCSR:A3DA4D64703 2009-12-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2009
Reliability and economic analysis of 2-out-of-3 redundant system with priority to repair S. Chander and R. K. Bhardwaj Full Length Research Paper Two reliability models have been developed to compare some reliability and economic measures for a 2-out-of-3 redundant system having two original units (called standard units) and one duplicate unit which areinitially taken as spare in cold standby. The system is considered in up-state if any two of original and/or duplicate units are operative in parallel mode. The original unit is inspected at its failure by the server to see the feasibility of repair. If repair is not feasible, it is replaced by a new original unit. However, repair of the duplicate unit is done without inspection. In model II, priority to repair the original unit over the duplicate unit is given. The failure time of the unit(s) is exponentially distributed while inspection and repair time distributions are assumed as arbitrary with different probability density functions. The semi-Markov process and regenerative point technique have been used to derive the expressions for mean time to system failure and profit of the models. A particular case is considered to highlight the results graphically. Key words: 2-out-of-3 system, inspection, priority to repair, reliability and economic measures. Academic Journals 2009 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/A3DA4D64703 http://dx.doi.org/10.5897/AJMCSR.9000106 en Copyright © 2009 S. Chander and R. K. Bhardwaj
oai:academicjournals.org:AJMCSR:9A858868756 2010-01-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
The efficiency of the linear classification rule in multi-group discriminant analysis Romain Lucas Glegrave;legrave; Kakaiuml;, Dieter Pelz and Rudy Palm Full Length Research Paper A Monte Carlo study was performed to assess the relative efficiency of the linear classification rule in 2, 3 and 5-group discriminant analysis. The simulation design took into account the number of variables (4, 6, 10, and 18), the size sample so that: = 1.5, 2.5 and 5. Three values of the overlap, e of the populations were considered (0.05; 0.1; 0.15) and their common distribution was normal, chi-square with 12, 8, and 4 df; the heteroscedasticity degree, was measured by the value of the power function of the homoscedasticity test related to (0.05; 0.4; 0.6; 0.8). For each combination of these factors, the actual empirically computed error rate was used to calculate the relative error, reof the rule. The results showed that for normal or homoscedastic populations, the efficiency of the rule became better for large number of groups. Non-normality or heteroscedasticity negatively impacted the performance of the rule whereas high values of the ratio n/p and high overlap have positive effect on the rule. The mean relative error of the rule became three times more important from homoscedastic to heteroscedasticity. Key words: Error rate, data samples, linear rule, multi-group, simulation. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/9A858868756 http://dx.doi.org/10.5897/AJMCSR.9000124 en Copyright © 2010 Romain Lucas Glegrave;legrave; Kakaiuml;, Dieter Pelz and Rudy Palm
oai:academicjournals.org:AJMCSR:0D675978744 2010-01-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
A robust method of estimating covariance matrix in multivariate data analysis G. M. Oyeyemi and R. A. Ipinyomi Full Length Research Paper We proposed a robust method of estimating covariance matrix in multivariate data set. The goal is to compare the proposed method with the most widely used robust methods (Minimum Volume Ellipsoid and Minimum Covariance Determinant) and the classical method (MLE) in detection of outliers at different levels and magnitude of outliers. The proposed robust method competes favourably well with both MVE and MCD and performed better than any of the two methods in detection of single or fewer outliers especially for small sample size and when the magnitude of outliers is relatively small. Key words: Covariance matrix, minimum volume ellipsoid (MVE), minimum covariance determinant (MCD), mahalanobis distance, optimality criteria. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/0D675978744 http://dx.doi.org/10.5897/AJMCSR.9000035 en Copyright © 2010 G. M. Oyeyemi and R. A. Ipinyomi
oai:academicjournals.org:AJMCSR:F3D562E8793 2010-02-28T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Invariance of numerical range under isometric transformation A. W. Wafula and J. M. Khalagai Short Communication In this paper, we look at some properties of isometries and conditions for a quasi-affinity to be unitary. Among other results it is proved that if A is a partial isometry such that either 0W(A) or 0W(An) for some positive integer n then A is unitary. Key words: Numerical range and unitary operator. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/F3D562E8793 http://dx.doi.org/10.5897/AJMCSR.9000074 en Copyright © 2010 A. W. Wafula and J. M. Khalagai
oai:academicjournals.org:AJMCSR:A6141528786 2010-02-28T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Relationship between continuity and momentum equation in two dimensional flow I. A. Idowu and J. B. Adewuyi Full Length Research Paper In this paper a quantitative discussion on a theory describing the relationship between the continuity and momentum equation in two dimensional flow together with the momentum equation in vectorial form: is reported. Via expanding in cylindrical polar coordinates, the end result is proved to be Euler equation. Key word: Continuity equation, momentum equation, cylindrical coordinates, polar coordinate. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/A6141528786 http://dx.doi.org/10.5897/AJMCSR.9000104 en Copyright © 2010 I. A. Idowu and J. B. Adewuyi
oai:academicjournals.org:AJMCSR:C89F5F18776 2010-02-28T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Conflict resolution using statistical approach O. Vincent Omwenga and N. Peter Mwita Full Length Research Paper Conflict can be described as a condition in which actions of one person prevent or compel some outcome at the resistance of the other. Quite often this can be seen as ldquo;two or more competing, often incompatible, responses to same eventrdquo;. In this paper, a statistical approach to conflict resolution using the concept of bargaining game theory is presented. The approach gives chances of failure that are minimal since any offer made in a conflict situation is tied to the likelihood of it being accepted as it takes into considerations the demands from the other party. The approach presents a fair way of solving a conflict without affecting a system. An employer-employee relationship was used to illustrate the application of the approach. Key words: Bargaining game theory, conflict, Ultimatum game. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/C89F5F18776 http://dx.doi.org/10.5897/AJMCSR.9000054 en Copyright © 2010 O. Vincent Omwenga and N. Peter Mwita
oai:academicjournals.org:AJMCSR:CC194D88841 2010-03-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Principal component procedure in factor analysis and robustness Joy Chioma Nwabueze Full Length Research Paper Principal component procedure has been widely used in factor analysis as a data reduction procedure. The estimation of the covariance and correlation matrix in factor analysis using principal component procedure is strongly influenced by outliers. This study investigates the robustness of principal component procedure in factor analysis by generating random variables from five different distributions which are used to determine the common and specific factors in factors analysis using principal component procedure. The results revealed that the variance of the first factor was widely distributed from distribution to distribution ranging from 0.6730 to 5.9352. The contribution of the first factor to the total variance varied widely from 15 to 98%. We conclude that the principal component procedure is not robust in factor analysis. Key words: Principal component, factor analysis, robustness, random variables, distributions. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/CC194D88841 http://dx.doi.org/10.5897/AJMCSR.9000101 en Copyright © 2010 Joy Chioma Nwabueze
oai:academicjournals.org:AJMCSR:8B6FF8D8812 2010-03-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Measuring the stress, strain and strain-rate in heat treated medium carbon steel samples and finding the constituted material related properties A. G. F. Alabi, T. K. Ajiboye and H. D. Olusegun Full Length Research Paper Mechanical failure of component parts as well as in build up structures can be prevented if proper quality control is carried out at point of componentrsquo;s manufacture. Engineers are known to analyze samples from which accurate predictions are made about the properties of the materials that are produced for the purpose of component and structural processing. This work had produced and tested heat treated 1030 steel by pulling them in tensometer to fracture. The tensometer was connected to a computer which plotted graphs from which data of true stress and strain were analyzed for the various heat treated specimens. The analysis of data was done using none regression analysis, SPSS soft ware, to obtain the materials related properties for each of the specimen. The yield strength (sy) and ultimate tensile strength (su) of the specimens were significantly different. The highest and lowest sywas annealed specimen 450 MPa and normalized specimen 220 MPa respectively. The highest and lowest su was hardened specimen 608 MPa and normalized specimen 320 MPa respectively. With a strain-rate sensitivity C of 0.0562, normalized specimen was less ductile than hardened specimen which had a C value of 0.0083. By the analysis, normalized and tempered specimen which had the strain hardening parameter n of 0.1270 and 0.1240 respectively were less ductile than hardened and annealed specimens with n values of 0.0439 and 0.0571 respectively. Key words: Yield strength, ultimate tensile strength, 1030 steel. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/8B6FF8D8812 http://dx.doi.org/10.5897/AJMCSR.9000078 en Copyright © 2010 A. G. F. Alabi, T. K. Ajiboye and H. D. Olusegun
oai:academicjournals.org:AJMCSR:73AABDC8862 2010-04-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Estimation of T- period’s ahead extreme quantile autoregression function Peter Nyamuhanga Mwita Full Length Research Paper This paper considers the estimation of extreme quantile autoregression function by using a parametric model. We combine direct estimation of quantiles in the middle region with that of extreme parts using the model and results from extreme value theory (EVT). The volatility used to scale the residuals is estimated indirectly, without estimating conditional mean, using the conditional quantile (CQ) range. The estimators are found to be consistent. A small simulation study carried out shows that the estimator of the volatility function converges to the true function over a range of distributional errors. Finally, the T-periods ahead extreme quantile autoregression function is given. Key words: Quantile, autoregression, value-at-risk, ARCH, extreme value theory,consistency, asymptotic normality. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/73AABDC8862 http://dx.doi.org/10.5897/AJMCSR.9000065 en Copyright © 2010 Peter Nyamuhanga Mwita
oai:academicjournals.org:AJMCSR:C73074E8852 2010-04-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Some structural compatibilities of pre A*-algebra A. Satyanarayana, J. Venkateswara and K. Rao Srinivasa Rao Full Length Research Paper A pre A*-algebra is the algebraic form of the 3-valued logic. In this paper, we define a binary operation on pre A*-algebra and show that is a semilattice. We also prove some results on the partial ordering which is induced from the semilattice. We derive necessary and sufficient conditions for pre A*-algebra (A,Ugrave;,Uacute;, (-)~) to become a Boolean algebra in terms of this partial ordering and binary operation and also find the necessary conditions for (A , ) as a lattice. Key words: Pre A*- algebra, poset, semilattice, centre, Boolean algebra. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/C73074E8852 http://dx.doi.org/10.5897/AJMCSR.9000119 en Copyright © 2010 A. Satyanarayana, J. Venkateswara and K. Rao Srinivasa Rao
oai:academicjournals.org:AJMCSR:7CCDDB28881 2010-05-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
New generalizations of generalized geometric series distributions Anwar Hassan Full Length Research Paper New generalizations of generalized geometric series distributions (NGOGGSD) and some of its subclasses are introduced. Recurrence relations and factorial moments are obtained. Several properties of NGOGGSD and its relations with other distributions are also discussed. Finally, a computer programmed in R-Software has been developed to ease the computations while estimating the parameters for data. Some sports sets of data have been fitted to the proposed model and comparison has been made with its subclasses. Key words: NGOGGSD, GGSD, GSD, ACEGGSD0, Quasi-uniform distribution, Bernoulli distribution. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/7CCDDB28881 http://dx.doi.org/10.5897/AJMCSR.9000086 en Copyright © 2010 Anwar Hassan
oai:academicjournals.org:AJMCSR:EB625EC8873 2010-05-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Heat transfer over an unsteady porous stretching surface embedded in a porous medium with variable heat flux in the presence of heat source or sink E. M. A. Elbashbeshy, D. M. Yassmin and A. A. Dalia Full Length Research Paper The unsteady boundary layer flow over a porous stretching surface embedded in a porous medium in the presence of heat source or sink is studied. The unsteadiness in the flow and temperature fields is caused by the time dependence of the stretching velocity and the surface heat flux. The governing partial differential equations are transformed into a system of ordinary differential equations, which is then solved numerically by applying shooting method using Runge-Kutta method. The solution is found to be dependent on the governing parameters including the Prandtl number, porous parameter, heat source /sink parameter, suction or injection parameter and unsteadiness parameter. Comparison of numerical results is made with previously published results under the special cases, and found to be in good agreement. Effects of the Prandtl number, porous parameter, heat source /sink parameter, suction or injection parameter and unsteadiness parameter on the flow and heat transfer are examined. Key words: Unsteady flow, boundary layer flow, stretching surface, heat transfer, porous medium and source /sink, suction or injection. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/EB625EC8873 http://dx.doi.org/10.5897/AJMCSR.9000071 en Copyright © 2010 E. M. A. Elbashbeshy, D. M. Yassmin and A. A. Dalia
oai:academicjournals.org:AJMCSR:CED75108915 2010-06-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
A mathematical model of radioimmunotherapy for tumor treatment Deepak Kumar and Sanjeev Kumar Full Length Research Paper There is rapidly growing interest in the potential for synergistic, clinically relevant therapeutic responses by combining radiation therapy with immune response. A new mathematical model of radioimmunotherapy for tumor treatment was introduced. In this work, the linear and exponential spatial dependence of tumor parameters was used. The dose distributions model of radiotherapy with immune response for tumor treatment was formulated. A discussion, on the effect of immune response with radiotherapy for the treatment of tumor is explained in details. Key words: Solid tumor, mathematical model, radioimmunotherapy, immune response. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/CED75108915 http://dx.doi.org/10.5897/AJMCSR.9000031 en Copyright © 2010 Deepak Kumar and Sanjeev Kumar
oai:academicjournals.org:AJMCSR:21F547C8905 2010-06-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
A novel analytical solution of steady flow over a rotating disk in porous medium with heat transfer by DTM-PADÉ Mohammad Mehdi Rashidi and Seied Amin Mohimanian Pour Full Length Research Paper In this study, the differential transform method (DTM) was applied to steady flow over a rotating disk in porous medium with heat transfer. The governing equations can be written as a system of nonlinear ordinary differential equations. The approximate solutions of these equations were obtained in the form of series with easily computable terms. Then, Padeacute; approximant was applied to increase the convergence radius of the series. The results obtained in this study were compared with the numerical results (fourth-order Runge-Kutta method). Key words: Padeacute; approximant, differential transform method, rotating disk, porous medium. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/21F547C8905 http://dx.doi.org/10.5897/AJMCSR.9000034 en Copyright © 2010 Mohammad Mehdi Rashidi and Seied Amin Mohimanian Pour
oai:academicjournals.org:AJMCSR:B4F5AD98898 2010-06-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Subclasses of analytic functions associated with Wright generalized hypergeometric functions G. Murugusundaramoorthy and N. Magesh Full Length Research Paper In this paper, we define a generalized class of starlike functions with negative coefficients and obtain coefficient estimates, distortion bounds, closure theorems and extreme points. Further we obtain modified Hadamard product, radii of close-to-convex, starlikeness and convexity for functions belonging to this class. Furthermore neighborhood results are discussed. Key words: Univalent functions, convex functions, starlike functions, -neighbourhood, inclusion relations, Hadamard product, Wright generalized hypergeometric functions. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/B4F5AD98898 http://dx.doi.org/10.5897/AJMCSR.9000122 en Copyright © 2010 G. Murugusundaramoorthy and N. Magesh
oai:academicjournals.org:AJMCSR:008CF138890 2010-06-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Computing leaf rectangularity index: An estimation problem when the parameter is a norm of a vector Isaac Didi Essi Full Length Research Paper A measure known as leaf rectangularity index (LRI) is estimated by means of bootstrap regression. The index, it is envisaged, will assist in discussing the geometry of leaf surfaces, if possible among different plants and across species. The study shows that one cannot obtain the point estimate of LRI before its interval estimate; rather, the interval estimate comes first before the point estimate. This paper gives the formal steps of obtaining both the point and interval estimate when the parameter is a norm of a vector. Key words: Leaf rectangularity index, bootstrap regression, norm. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/008CF138890 http://dx.doi.org/10.5897/AJMCSR.9000052 en Copyright © 2010 Isaac Didi Essi
oai:academicjournals.org:AJMCSR:B9189A08970 2010-07-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Norm properties of operators whose norms are Eigenvalues A. W. Wafula, J. M. Khalagai and G. Pokhariyal Full Length Research Paper In this paper we present properties of a norm-attaining operator on a Hilbert space and there implications. We show that if T has norm attaining vector then where the scalars are nonnegative numbers. Thus T satisfies a generalized Daugavet condition. Key words: Numerical range, eigenvalue, normalloid operator, Daugavet property. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/B9189A08970 http://dx.doi.org/10.5897/AJMCSR.9000089 en Copyright © 2010 A. W. Wafula, J. M. Khalagai and G. Pokhariyal
oai:academicjournals.org:AJMCSR:DC9CA0C8958 2010-07-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Visualization RCD (reinforced concrete design) table advisor for decision support activity L. O. Yusuf, O. Folorunso, A. T. Akinwale and I. A. Adejumobi Full Length Research Paper Reinforced concrete design (RCD) activity requires the services of design table to pick bar sizes and area of specific bar groups. This allow reinforced concrete (RC) designers to use their intuition to pick the right bar size for detailing of RC Structures which virtually enhance reliable and satisfactory answers to RCD problems. With the advent of computer with its powerful memory, most RCD software available automatically generates Steel Properties thus, jeopardising userrsquo;s contribution in terms of their perception. RCD Tables are conventionally small but not limited in use. By the skilful and innovative integration of available concepts and techniques, the power of the RCD Tables are enhanced to check for deflection, minimum and maximum area of steel, and display alert to users. Visualization RCD Table interface was designed as a dialog box. Simply Supported Reinforced Concrete Beam Structure (SSRCBS) tool was modified to accommodate the new tool. Statistical analysis revealed that the significance of time was borderline between SSRCBS tool and the modified tool. It was also found that as the tasks became more complex, the modified tool advantage increases in terms of task-by-task satisfaction and users understanding of the logic behind RCD. Key words: RCD visualization, RC, PDAs, SSRCBS, visRCD table advisor, DSS. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/DC9CA0C8958 http://dx.doi.org/10.5897/AJMCSR.9000130 en Copyright © 2010 L. O. Yusuf, O. Folorunso, A. T. Akinwale and I. A. Adejumobi
oai:academicjournals.org:AJMCSR:ADF38A08943 2010-07-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
A mobile-based knowledge management system for “Ifa”: An African traditional oracle Olusegun Folorunso, Adio T. Akinwale, Rebecca O. Vincent and Babatunde Olabenjo Full Length Research Paper Recently, the use of mobile applications in knowledge management systems has been a major discussion in some literatures. In the past, the authorrsquo;s conceptualized and designs a knowledge management system for ldquo;Ifardquo;. In this paper, a mobile application is designed which applies mobile knowledge management (mKM) to the ldquo;ifardquo; oracle consultation process implemented with the Netbeans 6.7.1 JavaME IDE and is compatible with MIDP 2.0 and CLDC 1.1 mobile devices. However, we address the potential suitability of mKM as a prototype model for mobile, quick information retrieval in the ldquo;ifardquo; oracle consultation process. This approach promotes the use of mobile technology and mobile knowledge management in African tradition. Key words: Mobile knowledge management, ldquo;ifardquo;, African tradition, expert system, Nigeria. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/ADF38A08943 http://dx.doi.org/10.5897/AJMCSR.9000032 en Copyright © 2010 Olusegun Folorunso, Adio T. Akinwale, Rebecca O. Vincent and Babatunde Olabenjo
oai:academicjournals.org:AJMCSR:EFF4B0D8934 2010-07-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Enhancing students interest in mathematics via multimedia presentation Nwaocha Vivian Ogochukwu Full Length Research Paper Alarming statistics in mathematics education in Nigeria indicated that very few or almost none of the students in high school fancy taking up a course in mathematics in the University. Moreover, less than ten percent of these students enjoyed lessons in mathematics. Additionally, cultural and racial prejudice as well as poverty are serious issues confronting many of today#39;s high school students, thus a set of thirty numerical equations to solve would not be top priority. Consequently, mathematics teachers have sought to determine how they could possibly capture the attention of teens distracted by serious problems and events in their daily lives. Although educators have made some efforts towards improving these trends, studentsrsquo; disinterest in continuing mathematics study beyond secondary school level is still a tremendous problem. In this paper, student preference of multimedia presentation in mathematics education as opposed to traditional instruction was investigated for high school students learning mathematics. The survey instrument presented a 5-point Likert scale with students rating 17 statements associated with acceptance of the presentation. Results from the survey carried out indicate that multimedia presentations can improve studentsrsquo; understanding, enthusiasm, class attendance and satisfaction. Key words: Class, high school, instruction, interest, mathematics, multimedia, student, teacher, traditional, University. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/EFF4B0D8934 http://dx.doi.org/10.5897/AJMCSR.9000062 en Copyright © 2010 Nwaocha Vivian Ogochukwu
oai:academicjournals.org:AJMCSR:DD336784880 2010-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
A stochastic iteration method for a class of variational inequalities in Hilbert space A. C. Okoroafor Full Length Research Paper Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/DD336784880 http://dx.doi.org/10.5897/AJMCSR.9000037 en Copyright © 2010 A. C. Okoroafor
oai:academicjournals.org:AJMCSR:63B876F4878 2010-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Appraising of Monte Carlo forecast in nonlinear econometric models Isaac D. Essi, E. N. Onwuchekwa and Gertrude C. Chikwendu Full Length Research Paper In the study, Monte Carlo (stochastic) and deterministic forecasts have been carried out. Though, as would be expected, there is reasonable gain in efficiency in the Monte Carlo forecast over the deterministic procedure. The extent of this gain depends on the relative dispersion criterion used. Key words: Monte Carlo forecast, deterministic forecast, efficiency Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/63B876F4878 http://dx.doi.org/10.5897/AJMCSR.9000010 en Copyright © 2010 Isaac D. Essi, E. N. Onwuchekwa and Gertrude C. Chikwendu
oai:academicjournals.org:AJMCSR:0AB2AB74874 2010-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
An empirical mathematical model for smoke attributed mortality B. O. Osu and C. Olunkwa Full Length Research Paper This paper presents a simple empirical mathematical model which predicts the increase in mortality caused by cigarette smoking. The model considers the introduction of new brands of cigarette in the market and (or) the introduction of new smokers in a given population. The model is used to predict the smoke attributed mortality (SAM) for a period of 20 years, say, using empirical data of Nigeria population. A means through which the government and the policy makers would use to control the SAM is suggested. Key words: Mortality, empirical mathematical model, smokers, government. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/0AB2AB74874 http://dx.doi.org/10.5897/AJMCSR.9000006 en Copyright © 2010 B. O. Osu and C. Olunkwa
oai:academicjournals.org:AJMCSR:4310A204870 2010-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
An improved chaotic encryption scheme K. A. Ayanlowo, O. Folorunso, A. T. Akinwale, A. N. Njah Full Length Research Paper In this paper, an attempt is made to develop a functional encryption scheme by exploiting the strength and redefining the operational limits of two related existing schemes. Various parameters used for comparative assessment show that the proposed scheme is better than the existing ones in terms of functionality, strength and suitability for applications in securing messages on networks and work files on stand-alone databases. Key words: Chaos, cryptography, logistic map. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/4310A204870 http://dx.doi.org/10.5897/AJMCSR.9000007 en Copyright © 2010 K. A. Ayanlowo, O. Folorunso, A. T. Akinwale, A. N. Njah
oai:academicjournals.org:AJMCSR:2531DDE4864 2010-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Population prediction using artificial neural network O. Folorunso, A. T. Akinwale,O. E. Asiribo and T. A. Adeyemo Full Length Research Paper Recently, the use of mobile applications in knowledge management systems has been a majordiscussion in some literatures. In the past, the authorrsquo;s conceptualized and designs a knowledge management system for ldquo;Ifardquo;. In this paper, a mobile application is designed which applies mobile knowledge management (mKM) to the ldquo;ifardquo; oracle consultation process implemented with the Netbeans 6.7.1 JavaME IDE and is compatible with MIDP 2.0 and CLDC 1.1 mobile devices. However, we address the potential suitability of mKM as a prototype model for mobile, quick information retrieval in the ldquo;ifardquo; oracle consultation process. This approach promotes the use of mobile technology and mobile knowledge management in African tradition. Key words: Mobile knowledge management, ldquo;ifardquo;, African tradition, expert system, Nigeria. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/2531DDE4864 http://dx.doi.org/10.5897/AJMCSR.9000017 en Copyright © 2010 O. Folorunso, A. T. Akinwale,O. E. Asiribo and T. A. Adeyemo
oai:academicjournals.org:AJMCSR:1D54FC24843 2010-08-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
An adaptive finite volume method using thin plate splines for the numerical simulation of the inviscid Burgers’ equation Terhemen Aboiyar Full Length Research Paper Thin plate splines are utilized in the construction of a non-oscillatory finite volume method for the inviscid Burgersrsquo; equation which is a prototype nonlinear conservation law. To capture the sharp features that occur during numerical simulation, the method is implemented on an adaptive triangulation. An a posteriori error indicator is used to detect regions where the solution varies rapidly. Key words: Finite volume methods, WENO method, conservation laws, radial basis functions, thin plate splines. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/1D54FC24843 http://dx.doi.org/10.5897/AJMCSR.9000005 en Copyright © 2010 Terhemen Aboiyar
oai:academicjournals.org:AJMCSR:624DD3F5044 2010-09-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
On discussion of the definition of probability Isaac Didi Essi, Joy C. Nwabueze and Zuonaki Ongodiebi Full Length Research Paper Mathematicians and scientists generally come to know the meaning of probability at a much latter stage of learning and research instead of getting it within the first two years in college or university. This work involving some random experiments with coins and dice, is an attempt to give first or second year students in the university a classroom demonstration of the approaches to the definition of probability and some of the possible drawbacks in these definitions. We have also used outcomes of the experiments to test for unbiasedness of the die and coin. All results have shown that the devices are unbiased. Key words: Probability, random experiments, unbiasedness. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/624DD3F5044 http://dx.doi.org/10.5897/AJMCSR.9000091 en Copyright © 2010 Isaac Didi Essi, Joy C. Nwabueze and Zuonaki Ongodiebi
oai:academicjournals.org:AJMCSR:1AC561C5019 2010-09-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Analytical model for I-V analysis of buried gate MESFET with modulation frequency characteristics T. Jaya and V. Kannan Full Length Research Paper The analysis of frequency-dependent characteristics of an ion-implanted buried-gate GaAs MESFET, with front side illumination has made achieving improved performance in I-V characteristics possible. When photo energy falls on the device, flow of charge carriers changes corresponding to the change in wave length and frequency of incident light. It has been observed that the channel conductance and I-V characteristic of buried gate increase. The data suggest that the magnitude of drain-to-source current increases, and as a result there are more uncovered ionic charges in the space charge region toward the drain-side of the gate. This analysis includes surface states and the ion implanted buried-gate process. The access charge density at the drain-side of the depletion induces opposite charges in the gate electrode. Consequently, it gives forward biasing to the Schottky barrier gate which increases with increasing values of Ids. As a result, the modulation of channel conductance and photo-voltage characteristics due to the buried-gate GaAs MESFET become highly effective. The results indicate very good performance of the device compared to other devices like MESFET under back illumination and MESFET with front illumination having surface gate. Key words: AC model optically illuminated field-effect transistor (OPFET), GaAs OPFET, optically controlled metalndash;semiconductorndash;field-effect transistor (MESFET). Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/1AC561C5019 http://dx.doi.org/10.5897/AJMCSR.9000041 en Copyright © 2010 T. Jaya and V. Kannan
oai:academicjournals.org:AJMCSR:C0FC17E5001 2010-09-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Calculation of the electron drift mobility in Cr2+:ZnS and Cr2+:ZnSe materials by rode iteration model H. Arabshahi Full Length Research Paper The results of electron drift velocity in Cr2+:ZnS, and Cr2+:ZnSe are calculated for different temperature, free-electron concentrations and compositions. The two-mode nature of the polar optic phonons is considered jointly with deformation potential acoustic, piezoelectric, alloy and ionized-impurity scattering. Band non-parabolocity, admixture of p functions, arbitrary degeneracy of the electron distribution, and the screening effects of free carriers on the scattering probabilities are incorporated. The Boltzmann equation is solved by an iterative technique using the currently established values of the material parameters. The iterative results are in fair agreement with other recent calculations obtained using the relaxation-time approximation and experimental methods. Key words: Boltzmann equation, electron drift velocity, deformation potential, piezoelectric. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/C0FC17E5001 http://dx.doi.org/10.5897/AJMCSR.9000047 en Copyright © 2010 H. Arabshahi
oai:academicjournals.org:AJMCSR:B3A70E24979 2010-09-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
On Monte Carlo forecast of production using nonlinear econometric models Isaac D. Essi, John .O. Olaomi and Joy .C. Nwabueze Full Length Research Paper In this study, Monte Carlo (stochastic) and deterministic forecasts have been carried out. The authors observe that there is reasonable gain in efficiency by Monte Carlo forecast over the deterministic procedure. Key words: Monte Carlo forecast, deterministic forecast, efficiency. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/B3A70E24979 http://dx.doi.org/10.5897/AJMCSR.9000092 en Copyright © 2010 Isaac D. Essi, John .O. Olaomi and Joy .C. Nwabueze
oai:academicjournals.org:AJMCSR:9C5DFE04969 2010-09-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Minimal strongly balanced changeover designs with first residuals V. K. Sharma, Yogita Gharde and Cini Varghese Full Length Research Paper Assuming the presence of first order residual effects, besides periods, experimental units and direct effects of treatments, a class of minimal strongly balanced changeover designs has been proposed. For v treatments, the designs require 2v experimental units for v/2 periods. It is seen that in terms of variances of estimated elementary contrasts in treatment effects, these designs are partially balanced based on the circular association scheme. The efficiency factors for the estimation of various treatment effects of the proposed designs relative to the orthogonal designs have been tabulated for v pound; 24. Key words: Minimal strongly balanced designs, changeover design, crossover designs, repeated measurements designs, residual effects, partially balanced changeover designs. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/9C5DFE04969 http://dx.doi.org/10.5897/AJMCSR.9000080 en Copyright © 2010 V. K. Sharma, Yogita Gharde and Cini Varghese
oai:academicjournals.org:AJMCSR:43B083F4953 2010-09-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Some properties of upper fuzzy order Mourad Oqla Massa#;deh Full Length Research Paper In this paper we shall study some properties for upper fuzzy subgroups, some lemma and theorem for this subject. Key words: Fuzzy set, upper fuzzy subgroups, upper normal fuzzy subgroups, upper fuzzy order. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/43B083F4953 http://dx.doi.org/10.5897/AJMCSR.9000117 en Copyright © 2010 Mourad Oqla Massa#;deh
oai:academicjournals.org:AJMCSR:94DF12B5756 2010-10-21T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
The data encryption standard thirty four years later: An overview Kenekayoro Patrick T. Full Length Research Paper The data encryption standard was the first encryption system to meet the National Institute of Standards and Technologyrsquo;s requirements for an encryption system, and also the first standardized encryption system. It was standardized in 1977 and since then, it has been subject to criticisms. The successor to the Data Encryption Standard, Advanced Encryption Standard has been developed and is used today but the Data Encryption Standard is still used today in industries. This paper overviewed the Data Encryption Standard; criticisms faced and concluded if it is still secure enough to protect our confidential information based on published cryptanalysis on this encryption system. Key words: Block ciphers, TDEA, DES, AES, cryptanalysis, encryption, decryption, cryptography. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/94DF12B5756 http://dx.doi.org/10.5897/AJMCSR.9000018 en Copyright © 2010 Kenekayoro Patrick T.
oai:academicjournals.org:AJMCSR:A66BB355329 2010-10-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
An inventory model with price breaks: Fuzzy approach J. K. Syed and Lahji Abdul Aziz Full Length Research Paper In this paper Fuzzy inventory model is developed with price breaks; a joint economic lot-size model is developed under Fuzzy environment. Optimum order quantity and optimum number of price breaks are obtained through the techniques of Fuzzy mathematics. Cost function of both buyer and seller is represented by Fuzzy membership function, and model is solved for optimum results by reformulating it as Fuzzy linear programming problem. For optimum solution of proposed problem, ldquo;LINDOrdquo; software is used. Key words: Fuzzy membership function, trapezoidal numbers, price breaks, defuzzification. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/A66BB355329 http://dx.doi.org/10.5897/AJMCSR.9000008 en Copyright © 2010 J. K. Syed and Lahji Abdul Aziz
oai:academicjournals.org:AJMCSR:0E776205314 2010-10-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Exploring Bayesian networks for medical decision support in breast cancer detection Jyotirmay Gadewadikar, Ognjen Kuljaca, Kwabena Agyepong, Erol Sarigul, Yufeng Zheng and Ping Zhang Full Length Research Paper The objective of this paper is to explore the implementation of a Bayesian Belief Network for an automated breast cancer detection support tool. It is intuitive that Bayesian networks are employed as one viable option for computer-aided detection by representing the relationships between diagnoses, physical findings, laboratory test results and imaging study findings. This work brings important entities such as Radiologists, Image Processing Scientists, Data Base Specialists and Applied Mathematicians on a common platform. A brief background concerning causal networks, probability theory and Bayesian networks is given; available computational tools and platforms are described. It is explained that, by exploiting conditional independencies entailed by influence chains, it is possible to represent a large instance in a Bayesian network using little space, and it is often possible to perform probabilistic inference among the features in an acceptable amount of time. The next steps towards realizing a Bayesian Belief Network Implementation are described. Bayesian networks have an unparallel advantage of being able to exploit the explicit structure of the domain model to derive a graphical representation for learning. The encoding of independencies in the network topology admits the design of efficient procedures for performing computations over the network. For the application of computer-aided detection in mammography, the researchers intend to design an interface between the project#39;s Bayesian network learning algorithm and the radiologists, so that the radiologists can have interaction with the system by labeling only a small number of informative images presented by the active learning algorithm. Key words: Bayesian networks, breast cancer, computer aided decision support. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/0E776205314 http://dx.doi.org/10.5897/AJMCSR.9000013 en Copyright © 2010 Jyotirmay Gadewadikar, Ognjen Kuljaca, Kwabena Agyepong, Erol Sarigul, Yufeng Zheng and Ping Zhang
oai:academicjournals.org:AJMCSR:ECB7EEA5297 2010-10-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
On Laguerre-Gaussians and Fredholm integral equations Terhemen Aboiyar, David A. Kuhe and Mrumun C. Soomiyol Full Length Research Paper The Gaussian and its generalization known as the Laguerre-Gaussians are used in this paper as a collocation basis for Fredholm integral equations of the second kind. The collocation points are chosen so that they coincide with the points around with the interpolant is translated. This leads to a linear system whose solution gives the coefficients of the interpolant. In this study, we have used two examples to illustrate the proposed method and the comparison between exact and numerical solutions shows that the proposed method provides a good approximation to the exact solution. Key words: Gaussians, Laguerre-Gaussians, Fredholm integral equations, collocation. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/ECB7EEA5297 http://dx.doi.org/10.5897/AJMCSR.9000015 en Copyright © 2010 Terhemen Aboiyar, David A. Kuhe and Mrumun C. Soomiyol
oai:academicjournals.org:AJMCSR:E939ABC5740 2010-10-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Transformation of emotion based on acoustic features of intonation patterns for Hindi speech S. S. Agrawal, Nupur Prakash and Anurag Jain Full Length Research Paper Changes in intonation patterns may convey not only different meaning but different emotions even if the sequence of speech segments are same in a sentence. The patterns change depending upon structure and emotion of the sentence and require being stored in speech database. It is a difficult and time-consuming task to store all utterances of all the expressive style, which also consumes huge memory space. So there should be an approach that minimizes the time and memory space for emotion rich database. A number of studies in this respect have been done for several languages and models developed. However, for Hindi not many studies have been done. Taking this fact in consideration the intonation patterns have been studied for different languages in this paper and analysed for Hindi language. On the basis of dense research on intonation pattern an algorithm has been proposed for emotion conversion. This algorithm only requires storing neutral utterances in the database and other expressive style utterances can be derived from these neutral emotion. Proposed algorithm is based on linear modification model (LMM), where fundamental frequency (F0) is one of the factors to convert emotions. To perform the experiments, an intonational rich database is maintained for four expressive styles; surprise, happiness, anger and sadness. The perception tests also carried out, where group of listeners were asked to listen to the utterances from database and judge the emotion. This perception test involves classification of the emotions already available in the database by the listener and to judge the quality of converted neutral utterances. The results are analysed for four emotions: happiness, anger, surprise and sadness and performance of the experiment is evaluated. The accuracy of perception test on transformed emotions was found out to be 95% for surprise and 93.4% for sadness 82% for happiness and 96.7% for anger. Key words: Intonation patterns, intonational database, emotion conversion, fundamental frequency (F0), perception test. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/E939ABC5740 http://dx.doi.org/10.5897/AJMCSR.9000019 en Copyright © 2010 S. S. Agrawal, Nupur Prakash and Anurag Jain
oai:academicjournals.org:AJMCSR:DD2AF025717 2010-10-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Combined influence of Soret and Dufour effects on convective heat and mass transfer flow through a porous medium in cylindrical annulus with heat sources P. Sudarsan Reddy and D. R. V. Prasada Rao Full Length Research Paper The heat and mass transfer characteristics of non-Darcy mixed convective flow of a viscous electrically conducting fluid through a porous medium in a circular cylindrical annulus in the presence of temperature gradient heat sources with Soret and Dufour effects have been analyzed. The partial differential equations governing the problem under consideration are transformed into a system of ordinary differential equations and are solved numerically by using the Galerkin finite element method. The velocity, temperature and concentration profiles are presented graphically for various values of the parameters. Key words: Heat transfer, mass transfer, Soret effects, Dufour effect, and temperature gradient heat sources. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/DD2AF025717 http://dx.doi.org/10.5897/AJMCSR.9000011 en Copyright © 2010 P. Sudarsan Reddy and D. R. V. Prasada Rao
oai:academicjournals.org:AJMCSR:5ED49875850 2010-11-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
A study on Agile Software Testing: Emergence and techniques B. K. Madhu, Megha Jigalur and V. Lokesha Full Length Research Paper Customer satisfaction, quick and efficient delivery of finished products is all that is needed to lead the way in addressing issues regarding numerous software life cycles. Starting from waterfall model to any present life cycle, we find various advantages and disadvantages to be implemented in software development. Software testing is the state that takes the much of elapse time of SDLC. Improving the testing time and optimizing the techniques will always result in fast and efficient finish of software product. In this direction, Agile Software Development (ASD) is a new tool addressing most of the issues encountered. As in ASD, Agile Software Testing (AST) carries the manifesto of agile methodology and follows the highest techniques and best practices of software testing life cycle. Though AST is used in many Product-Based Software Company, the optimal procedure and superior techniques yielding better results are yet to be discovered. This paper is aimed at guiding and forming a hub for all agile testing practitioners in addressing these issues. It also lists advantages of agile testing and core techniques of implementation process in AST. Key words: Software development life cycle (SDLC), agile software development (ASD), agile software testing (AST). Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/5ED49875850 http://dx.doi.org/10.5897/AJMCSR.9000004 en Copyright © 2010 B. K. Madhu, Megha Jigalur and V. Lokesha
oai:academicjournals.org:AJMCSR:21B8C3D5827 2010-11-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
A note on indirect least squares and matrix partitioning Isaac D. Essi, N. M. Nafo and E. H. Amadi Full Length Research Paper At times, it is discovered that in using OLS in estimating an equation, inconsistent estimates are obtained because of correlation between the independent variable and the stochastic disturbance term. In such a circumstance, it is likely that the equation so estimated belongs to a wider family of equations related to the practical situation under consideration. Inevitably, a model describing the joint dependence of variables, called simultaneous ndash; equation model evolves. In order to obtain consistent estimator, one may resort to indirect least squares (ILS) or two ndash; stage least squares (2SLS). For an over-identified system, ILS through unguided coefficient technique (UCT) produces non-unique estimates for a just identified equation. Unique estimates can only be possible if ILS is approached through matrix partition techniques (MPT). The authorsrsquo; objective in this paper is to prove the proposition stated above. The definitions of UCT and MPT are also given in the paper. Key words: Least squares, matrix partitioning, unguided coefficient technique, matrix partition technique, simultaneous equation model. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/21B8C3D5827 http://dx.doi.org/10.5897/AJMCSR.9000003 en Copyright © 2010 Isaac D. Essi, N. M. Nafo and E. H. Amadi
oai:academicjournals.org:AJMCSR:C7EF9665813 2010-11-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Consistent estimators of intrinsically linear econometric model of the Nigerian economy Nwabueze Joy Chioma and E. Nworuh Godwin Full Length Research Paper This study compares the simulation performance of an operational econometric model of the Nigerian economy. Five estimators namely OLS, 2SPC4, 2SPC6 and 2SPC8 were used to obtain consistent estimators of the structural parameters in an econometric model of the Nigerian economy when some of the equations are non-linear but intrinsically linear. The performance of the estimators was ranked using Friedmanrsquo;s test statistics based on four criteria namely, root mean square error (RMSE), Theils inequality coefficients, bias and variance proportions. The result of this ranking show that 2SPC6 and 2SPC8 emerged as the best estimators. The least preferred estimators were the OLS and 2SPC4 in that order. Key words: Intrinsically linear model, non-linear, econometric, Friedman test statistic, root mean square error. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/C7EF9665813 http://dx.doi.org/10.5897/AJMCSR.9000012 en Copyright © 2010 Nwabueze Joy Chioma and E. Nworuh Godwin
oai:academicjournals.org:AJMCSR:3A4284C5792 2010-11-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Application of factor analysis to data on improved cassava varieties cultivated in Nigeria Nwabueze, Joy Chioma Full Length Research Paper This study adopted the multivariate methods to analyze a set of data on the proximate composition of fufu flours processed from 43 different Cassava Mosaic Disease (CMD) resistant varieties from International Institute of Tropical Agriculture (IITA) Onne, Port Harcourt, Nigeria. The factor analysis of the data showed that four components were significant (P lt; 0.05) for reducing and detecting the structure of the data. Seventy eight percent of the total variance was explained by these core components. The first component accounted for 26.37% of the total variance, the second 21.90%, the third 15.43% and the fourth 14.77%. The scree plot of data lent credence to the four components retained. Key words: Factor analysis, multivariate methods, principal component, proximate composition, scree plot, cassava varieties, cassava mosaic disease. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/3A4284C5792 http://dx.doi.org/10.5897/AJMCSR.9000009 en Copyright © 2010 Nwabueze, Joy Chioma
oai:academicjournals.org:AJMCSR:2D11E2D5965 2010-12-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
A metaheuristic and PTAS approach for NP-hard scheduling problem with controllable processing times Hamed Bayat, Hassan Akbari and Hamid Davoudpour Full Length Research Paper Most of the applied and interesting problems in industry and real world are difficult to solve. These problems are often NP-hard and the problem in this paper is strongly NP-hard. Approximation and metaheuristic algorithms are used to find a solution to these problems. In this paper we have used a polynomial time approximation algorithm, this algorithm is a suboptimal approach that provably works fast and that provably yields solutions of very high quality. In this paper, the problem of scheduling jobs on a single machine with controllable processing times is considered. The fact that the n jobs have controllable processing times means that it is possible to reduce the processing time of the jobs by paying a certain cost. In this paper, each job has a release date when it becomes available for processing, and, after completing its processing, requires an additional delivery time. Furthermore, preemption is allowed. The preemptive version allows an operation to be interrupted and continued at a later time. Feasible schedules are further restricted by job precedence constraints. The algorithm in this paper gives a substantial improvement for the special case without controllable processing times obtained by Hall et al. (1989) and the special case with controllable processing times by Mastrolilli (2009). In this paper we added controllable processing time instead fixed processing time and preemption to the problem. Moreover, we develop a polynomial time approximation scheme whose running time depends only linearly on the input size. This improves and generalize the previous 3/2+epsilon;-approximation algorithm by Mastrolilli (2009). At last it will be shown that the problem with its constraints has a polynomial time approximation scheme. It means that for any given epsilon;, a polynomial algorithm exists for the problem. It will be shown by a numerical example finally. Key words: Scheduling, controllable processing times, polynomial time approximation scheme (PTAS), metaheuristic methods, computational complexity, intractable problems Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/2D11E2D5965 http://dx.doi.org/10.5897/AJMCSR.9000002 en Copyright © 2010 Hamed Bayat, Hassan Akbari and Hamid Davoudpour
oai:academicjournals.org:AJMCSR:083CD735938 2010-12-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Performance analysis of QoS in PMP mode WiMAX networks Harwinder Singh and Maninder Singh Full Length Research Paper IEEE 802.16 standard supports two different topologies: Point to multipoint (PMP) and mesh. In this paper, a QoS mechanism for point to multipoint of IEEE 802.16 and BS scheduler for PMP mode is proposed. This paper also describes quality of service over WiMAX networks. Average WiMAX delay, average WiMAX load and average WiMAX throughput at base station is analyzed and compared by applying different scheduler at base station and at fixed nodes. Key words: QoS, PMP mode, WiMAX networks, wireless networks. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/083CD735938 http://dx.doi.org/10.5897/AJMCSR.9000016 en Copyright © 2010 Harwinder Singh and Maninder Singh
oai:academicjournals.org:AJMCSR:94EA7105914 2010-12-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
A dynamic programming approach to optimal manpower recruitment and promotion policies for the two grade system S. Nirmala and M. Jeeva Full Length Research Paper Many manpower models play a dominant role in efficient design and control of manpower system. In this paper, a mathematical model has been developed with the objective of minimizing the manpower system cost during the recruitment and promotion period which are determined by the changes that take place in the system. It resulted in the form of recursive optimization, a dynamic programming, which has been found to be analogous to the Wagner ndash; Whitin model in the production and inventory management. Key words: Recruitment, promotion, dynamic programming and manpower planning. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/94EA7105914 http://dx.doi.org/10.5897/AJMCSR.9000001 en Copyright © 2010 S. Nirmala and M. Jeeva
oai:academicjournals.org:AJMCSR:F77EE7B5894 2010-12-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2010
Key exchange scheme with higher security and its analysis H. K. Pathak and Manju Sanghi Full Length Research Paper Proposed paper gives a secure key exchange scheme using block upper triangular matrices of higher order. By using this method it is possible to generate keys of large orders without the need of large primes thereby avoiding the common ciphertext attacks. The element used for generating shared key is the element of (1, 3) block of the matrix which depends upon the elements of (1, 2) as well as on the (2, 3) blocks thereby increasing the hardness of the problem and providing greater security. Moreover our proposal is compared with the method proposed by Alvarez et al. (2009) Key words: Block upper triangular matrices, public key cryptography, polynomial matrices, DH key exchange. Academic Journals 2010 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/F77EE7B5894 http://dx.doi.org/10.5897/AJMCSR.9000014 en Copyright © 2010 H. K. Pathak and Manju Sanghi
oai:academicjournals.org:AJMCSR:E86DAAE1583 2011-01-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
A mathematical approach to transportation related data of South Assam for the optimal age of replacement of a vehicle and daily expenditure minimization Nabendu Sen, Banashri Sinha and Tanmoy Som Full Length Research Paper This paper deals with the replacement issue of an Omni bus plying on Silcharndash;Guwahati route in India under government and private travel agencies and daily expenditure minimization of travel agencies. In this paper, effort has been given to study the age at which a bus should be replaced on the basis of various expenditure on it. It also attempts to calculate how to minimize daily expenditure of a bus service providing agency with some constraints. The post optimality of the L.P models will be studied at the end .We find the literature of it in various standard books and journals (Hartly, 1969; Harvey, 1969) as listed in the reference section. We find literature for formulation of LP models in (Sen and Som, 2008a, b, c; Sen, 2008d). In (Sen and Som, 2008a), models were developed to maximize daily profit of a service unit while in (Sen and Som, 2008b), a model was developed to minimize passenger fare. Key words: Omnibus, scrap value, running cost, E-class. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/E86DAAE1583 http://dx.doi.org/10.5897/AJMCSR.9000030 en Copyright © 2011 Nabendu Sen, Banashri Sinha and Tanmoy Som
oai:academicjournals.org:AJMCSR:C7749D81563 2011-01-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Ample invertible sheaves on the irreducible components of an exceptional locus D. Alexiou and Farhan Ismail Full Length Research Paper Resolving the -dimensional -Singularity, an exceptional locus will be obtained (), where are the irreducible components of , and they are isomorphic to. These are invertible sheaves. We study the conditions to be ample, using the known Kleiman#39;s Criterion Kleiman (1966). Key words: Simple singularity, exceptional locus, ample sheaves. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/C7749D81563 http://dx.doi.org/10.5897/AJMCSR.9000039 en Copyright © 2011 D. Alexiou and Farhan Ismail
oai:academicjournals.org:AJMCSR:DFE07351593 2011-01-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Location of ambulance emergency medical service in the Kumasi Metropolis, Ghana S. K. Amponsah, Gordon Amoako, K. F. Darkwah and E. Agyeman Full Length Research Paper Location of emergency medical services such as an ambulance in urban locations has been under study for a long time. Several approaches have been employed in solving this very sensitive location problem. In this paper, a case study of the ambulance location problem in an urban setting as the Kumasi metropolis in Ghana is solved. The Non-Linear Maximum Expected Covering Location Problem (MEXCLP) implemented by Saydam and Aytug (2003) was used. To solve the problem, Genetic Algorithms (GA) that uses random key coding was implemented. A formula for renormalization has been introduced. Real route distances were used for computation and statistical deviation was introduced in the selection of our optimal route. Key words: Location, maximum expected covering location problem, genetic algorithm. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/DFE07351593 http://dx.doi.org/10.5897/AJMCSR.9000075 en Copyright © 2011 S. K. Amponsah, Gordon Amoako, K. F. Darkwah and E. Agyeman
oai:academicjournals.org:AJMCSR:251107D1609 2011-01-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Modified extended median test Oyeka I. C. A. and Uzuke C. A. Full Length Research Paper This paper proposes a modified extended median test that adjusts for the effects of any possible ties in the specific data. The proposed method is illustrated with data. A comparison with the extended median test suggests that the proposed method is at least as powerful as the extended median test.In this study, the proposed extended median test presents an example indicating that the proposed modified extended median test is more powerful than the ordinary extended median test. Key words: Median test, tied observation, chi-square, P-value, chi;2 distribution. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/251107D1609 http://dx.doi.org/10.5897/AJMCSR.9000083 en Copyright © 2011 Oyeka I. C. A. and Uzuke C. A.
oai:academicjournals.org:AJMCSR:64A61231618 2011-01-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Testing the equality of central tendency measures using various trimming strategies Zahayu Md Yusof, Suhaida Abdullah, Sharipah Soaad Syed Yahaya and Abdul Rahman Othman Full Length Research Paper Ft statistic test is a non classical method of comparing two or more groups. This statistical procedure is able to handle problems of sample locations when non-normality occurs but the homogeneity of variances assumption still applies. This method is not robust under the existence of variance heterogeneity. To make this test less sensitive when either one or both of the common assumptions are violated, in this study the test is modified and improved by replacing the testrsquo;s original central tendency measure that is, the fixed symmetric trimmed mean with a predetermined asymmetric trimmed mean and a modified one-step M-estimator (MOM) trimmed mean. The finding shows that when the data is suspected to be extremely skewed, then, it will be advantageous to adopt MOM procedures for homogeneous variance cases. On the other hand, for heterogeneous variances, a trimmed mean which uses predetermined asymmetric trimmed mean should be considered as an alternative, particularly for testing the equality of four groups. Key words: Heterogeneity, asymmetric, trimmed mean, MOM, robustness. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/64A61231618 http://dx.doi.org/10.5897/AJMCSR.9000123 en Copyright © 2011 Zahayu Md Yusof, Suhaida Abdullah, Sharipah Soaad Syed Yahaya and Abdul Rahman Othman
oai:academicjournals.org:AJMCSR:0468BAB1659 2011-02-28T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Evaluation of continuous host-parasitoid models Siza Mwalusepo, Henri E. Z. Tonnang and Estomih S. Massawe Full Length Research Paper In this paper the performance of continuous host-parasitoid models were investigated. The parameter values for several well-known models: Lotka-volterra, Holling Tanner Type 2, Holling Tanner Type 3, Leslie, Bazykin, Beddington-DeAngelis, Yodzis and Rosenzwing-Macarthur models were estimated. The models were tested on 40 consecutive sets of time series data collected at 14 days interval for pest and parasitoid population obtained from a highland cabbage growing area in Eastern Kenya. Model parameters were estimated from the minimization of the loss functions between the theoretical and experimental time series datasets following the Nelder-Mead multidimensional method. Initial values of population size and parameters were randomly chosen. Durbin-Watson statistic was applied for comparison of model outputs and experimental population trajectories. Among the eight different host-parasitoid models, Holling Tanner model Type 3 presented relatively better approximations compared to the other models. Key words: Diamondback moth, population dynamics, model parameters estimation, biological control, parasitoid impact. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/0468BAB1659 http://dx.doi.org/10.5897/AJMCSR.9000067 en Copyright © 2011 Siza Mwalusepo, Henri E. Z. Tonnang and Estomih S. Massawe
oai:academicjournals.org:AJMCSR:5909CED1675 2011-02-28T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Department of Computer Science, University of Peshawar, Peshawar, Khyber Pakhtoonkhwa, Pakistan. Muhammad Bilal, Mohammad Abid Khan, Rahman Ali and Rashid Ahmed Full Length Research Paper A natural language contains a variety of ambiguities. From a computational point of view, it is very difficult to cope with these ambiguities. Syntactic ambiguity arises from the relationship between the words and clauses of a sentence, not from the range of meanings of single words. Here, a knowledge-based adaptive approach has been proposed to resolve the syntactic ambiguities in Pashto text. The resolution involves user interaction with the system to select the appropriate meaning of the ambiguous phrase from a set of possible meanings stored in the knowledge base of the system. The user can add a new meaning to the knowledge base, for a particular phrase, if it is not there. The system has been tested on a raw Pashto corpus and resulted in accuracy of 90%. Key words: Ambiguity, Pashto, syntactic ambiguity, syntactic ambiguity resolution, algorithm. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/5909CED1675 http://dx.doi.org/10.5897/AJMCSR.9000058 en Copyright © 2011 Muhammad Bilal, Mohammad Abid Khan, Rahman Ali and Rashid Ahmed
oai:academicjournals.org:AJMCSR:31896D81697 2011-02-28T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Fuzzy multi-objective linear programming for traveling salesman problem Arindam Chaudhuri and Kajal De Full Length Research Paper Traveling Salesman Problem (TSP) is an important problem in Artificial Intelligence and Operations Research domain. The problem has been investigated under different headings and solved with various approaches including soft computing and linear programming. The conventional linear programming deals with crisp parameters. However, information available in real life system is of vague, imprecise and uncertain nature. The impreciseness and uncertainty aspects are handled using Fuzzy Sets to obtain optimal solutions. Multi-Objective Linear Programming effectively deals with flexible aspiration levels or goals. Fuzzy Multi-Objective Linear Programming enhances the effectiveness of solutions with acceptable solutions through fuzzy constraints. In this work, Fuzzy Multi-Objective Linear Programming is used for solving TSP with vague and imprecise parameters. An example of TSP with multiple objectives and imprecise parameters is also discussed. Key words: Traveling salesman problem, fuzzy multi-objective linear programming, multiple objectives, vague parameters, aspiration levels. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/31896D81697 http://dx.doi.org/10.5897/AJMCSR.9000069 en Copyright © 2011 Arindam Chaudhuri and Kajal De
oai:academicjournals.org:AJMCSR:7134AD11708 2011-02-28T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Transmission dynamics of infectious diseases by immigrants in a vaccinated and temporary immune protected population Helikumi Mlyashimbi, Estomih S. Massawe and Daniel Makinde Full Length Research Paper In this paper, a mathematical model of infectious diseases by immigrants in a vaccinated and temporary immune protected population has been investigated. The model incorporates the assumption that immigrant individuals enter in the respective population with an immunity received from either vaccination or recover from the disease. The stability of the system has been analyzed for the existence of the disease-free and endemic equilibrium points, and it has been shown that the disease free equilibrium point is asymptotically stable when an effective reproduction number is less than unity and unstable when an effective reproduction number is greater than unity. From the analysis of the model, it is shown that vaccination coverage is greater than the vaccination; otherwise the disease will persist within the community. It is also shown that the increase of immigrants in a population tends to lower the first dose-vaccination coverage, hence the disease become endemic in the population. Numerical simulations of the model showed that in the absence of the immigrants, the disease can be eradicated in a population with a single-dose vaccination only. Key words: Immune protection, infectious diseases, infections by immigrants, disease transmission, recovered individuals, vaccinated population. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/7134AD11708 http://dx.doi.org/10.5897/AJMCSR.9000128 en Copyright © 2011 Helikumi Mlyashimbi, Estomih S. Massawe and Daniel Makinde
oai:academicjournals.org:AJMCSR:82F8EB61723 2011-03-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
A class of one-point zero-stable continuous hybrid methods for direct solution of second-order differential equations S. J. Kayode Full Length Research Paper This paper considers the development of a class of one-point hybrid implicit methods for direct solution of general second order ordinary differential equations. The main predictors needed for the evaluation of the implicit methods are obtained to be of the same order with the methods at whatever hybrid point of collocation. The methods and their respective predictors are consistent and zero-stable. Numerical results are presented to show the accuracy of the methods. Key words: One-point continuous hybrid, collocation and interpolation equations, grid point Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/82F8EB61723 http://dx.doi.org/10.5897/AJMCSR.9000025 en Copyright © 2011 S. J. Kayode
oai:academicjournals.org:AJMCSR:A25BD9E2247 2011-03-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
A comparative study of a class of implicit multi-derivative methods for numerical solution of non-stiff and stiff first order ordinary differential equations Famurewa O. K. E, Ademiluyi R. A. and Awoyemi D. O. Full Length Research Paper This work describes the development, analysis, implementation and a comparative study of a class of Implicit Multi-derivative Linear Multistep methods for numerical solution of non-stiff and stiff Initial Value Problems of first order Ordinary Differential Equations. These multi-derivative methods incorporate more analytical properties of the differential equation into the conventional implicit linear multistep formulae and vary the step-size (k) as well as the order of the derivative (l) to obtain more accurate and efficient methods for solution of non-stiff and stiff first order ordinary differential equations. The basic properties of these methods were analyzed and the results showed that the methods are accurate, convergent and A-stable. Hence, suitable for the solution of non-stiff and stiff initial value problems of ordinary differential equations. A comparative study of the newly developed methods are carried out to determine the effect of increasing the step-size (k) and the order of the derivative (l). The result showed a remarkable improvement in accuracy and efficiency as the step-size (k) and the order of the derivative (l) are increased. Key words: Implicit, Multi-derivative, Multi-step, Non-stiff, Stiff, Ordinary and Differential equation. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/A25BD9E2247 http://dx.doi.org/10.5897/AJMCSR.9000028 en Copyright © 2011 Famurewa O. K. E, Ademiluyi R. A. and Awoyemi D. O.
oai:academicjournals.org:AJMCSR:09C41A91731 2011-03-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Application of multi criteria decision making technique to evaluation suppliers in supply chain management Mohammad Saeed Zaeri, Amir Sadeghi, Amir Naderi, Abolfazl Kalanaki Reza Fasihy, Seyed Masoud Hosseini Shorshani, and Arezou Poyan Full Length Research Paper Supplier selection, the process of determining the suitable suppliers who are able to provide the buyer with the right quality products and/or services at the right price, at the right time and in the right quantities, is one of the most critical activities for establishing an effective supply chain. In other words, supplier selection is a multi-criteria decision making problem which includes both qualitative and quantitative factors. In order to choose the best suppliers, it is essential to make a trade-off between these tangible and intangible factors, some of which may conflict. The aim of this study is developing a methodology to evaluate suppliers in supply chain cycle based on Technique for Order Preference by Similarity to Ideal Solution method (TOPSIS). The authors, with the help of going over expertise of experts and their relevant specialized literature, could recognize variables and effectivecriteria in supplier selection. After, the weights for a number of criteria are calculated based on the opinions of experts; these weights are inputted to the TOPSIS method to rank suppliers. Finally, this methodology is done by a numerical example, then, the rank of each supplier is determined according to its results. Key words: Supplier selection problem, technique for order preference by similarity to ideal solution method (TOPSIS Method), supplier management, multi criteria decision making, outsourcing, supply chain management. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/09C41A91731 http://dx.doi.org/10.5897/AJMCSR.9000042 en Copyright © 2011 Mohammad Saeed Zaeri, Amir Sadeghi, Amir Naderi, Abolfazl Kalanaki Reza Fasihy, Seyed Masoud Hosseini Shorshani, and Arezou Poyan
oai:academicjournals.org:AJMCSR:7063CC62149 2011-03-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Optimal packing of fm station progammes case study: Kaase Fm Station, Kumasi, Ghana S. K. Amponsah, K. F. Darkwah and F. K. Awuah Full Length Research Paper A FM station has a pile of programmes being broadcast in the testing phase of the station. The programmes consist of fixed and unfixed programmes. However the full complement of programmes has not been reached. To achieve full complement, the station wants to plan a new programme mix with fixed programmes retaining their original time slots. The rearrangement of the programmes is modeled as a variant of packing problem. We introduce a model, which is a modification of the generalized assignment problem with identified first-use bins of Shraideh et al. (2008). Our model seeks to minimize wasted air time that results out of the new programme arrangement. The results are obtained using the modified simple bin packing algorithm, which is also a modification of the simple bin packing algorithm of Amponsah (2003). The new arrangement of programmes produces a total of zero minutes of wasted air time. Key words: Packing, algorithm, FM station, assignment. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/7063CC62149 http://dx.doi.org/10.5897/AJMCSR.9000097 en Copyright © 2011 S. K. Amponsah, K. F. Darkwah and F. K. Awuah
oai:academicjournals.org:AJMCSR:37D10622168 2011-03-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Semantic web - The future of the web Kenekayoro Patrick T. Review The web has grown steadily since its inception in 1990. Websites developed today are now tagged as Web 2.0; that is, they are user oriented and allow distributed publishing. Web 2.0 still follows the principle of the early web, a system of interlinked documents without organization. To onus was on the developers to design web applications that allow user interaction. The semantic web is the next generation of the web; its aim is to make the web a system where all data are interconnected thus bringing organization to the web. This paper reviews the technologies of the current web, semantic web and its application areas. Key words: Semantic web, OWL, RDF, sparql, web 3.0, ontology, www, web 2.0. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/37D10622168 http://dx.doi.org/10.5897/AJMCSR.9000109 en Copyright © 2011 Kenekayoro Patrick T.
oai:academicjournals.org:AJMCSR:B5BF40B2179 2011-03-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Some inequalities of a formula of population size due to epidemics model problem Hemant Kumar Short Communication In the present paper, we evaluate a formula of population size due to epidemics model problem for communicable diseases, in which the daily contact rate is supposed to be varied with population size N(t) that is large, so that it is considered as a continuous variable of time (t). Then, we obtain some inequalities of above analytic formula of population size that are useful to plot some graphs on population dynamics of the system. Key words: Population size, epidemics model, hypergeometric function, inequalities, communicable diseases. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/B5BF40B2179 http://dx.doi.org/10.5897/AJMCSR.9000116 en Copyright © 2011 Hemant Kumar
oai:academicjournals.org:AJMCSR:3B78B4F2286 2011-03-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Nonlinear analysis of a fractional reaction diffusion model for tumour invasion Atabong T. A. and M. O. Oyesanya Full Length Research Paper Mathematical models in general and Reaction Diffusion Models in particular have been rigorously studied and applied in different forms to explain situation in biomedical and allied sciences including the complex tumour microenvironment. They have been proven to be really significant in cancer research. The not so extensively known fractional reaction-diffusion model is presented in this research as a plausible model for the invasion of tumour and its consequences in the human organ in which it resides. In this model we make use of fractional derivatives as a replacement for the normal derivatives to express the diffusion of the tumour cells, normal cells and hydrogen ion concentration. The nonlinear analysis of this model predicts that a death situation always arise if some of the parameters are of a certain magnitude. In this situation, the tumour cells population increases (with an eventual bound after death) by eating up all the normal cells of their host organ. Effectively, the model predicts that the relative interaction between the tumor and normal cells population gives rise to a bifurcation parameter for which a Hopf bifurcation occurs between the period of attack and death. Also the death situation using this model comes faster than the predictions of other models for tumour invasion. This research may therefore give a useful indication of the possible timing of the drugs and dosages required for the treatment or control of tumour progression in human. Key words: Tumour, fractional reaction diffusion equation, trotter product formula, hopf bifurcation, vasculature, oxygenation, Hypoxia. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/3B78B4F2286 http://dx.doi.org/10.5897/AJMCSR.9000088 en Copyright © 2011 Atabong T. A. and M. O. Oyesanya
oai:academicjournals.org:AJMCSR:BEDC8BB2296 2011-03-31T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
On best 1:1 codes for generalized quantitative-qualitative measure of inaccuracy Priti Gupta, Niranjan and Hari Arora Full Length Research Paper In coding theory, generally, we come across the problem of efficient coding of messages to be sent over a noiseless channel and attempt to maximize the number of messages that can be sent through a channel in a given time. Therefore, we find the minimum value of a mean codeword length subject to a given constraint on codeword lengths. As the codeword lengths are integers, the minimum value lies between two bounds, so, a noiseless coding theorem seeks to find these bounds for a given mean and a given constraint. In this paper, we are modifying the noiseless coding theorem as obtained by Bilal and Pirzada (2006) for binary, as well as D size 1:1 codes. The coding theorem as obtained by us is less constrained. Key words: Quantitative-qualitative measure, inaccuracy, noiseless coding theorem. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/BEDC8BB2296 http://dx.doi.org/10.5897/AJMCSR.9000090 en Copyright © 2011 Priti Gupta, Niranjan and Hari Arora
oai:academicjournals.org:AJMCSR:5C867A62346 2011-04-30T00:00:00Z AcademicJournals AJMCSR AJMCSR:2011
Approximation formulae for phase shifts of s–wave Schrödinger equation due to binomial potential and their applications Hemant Kumar and Vimal Pratap Singh Full Length Research Paper In this paper, we derive the approximation formulae for phase shifts of s-wave Schrouml;dinger equation on introducing binomial potential function and then make their applications to study the fluctuations in the phase shift difference from the s-wave with respect to different values of the arbitrary parameter occurring in a given binomial potential function. Key words: S-wave Schrouml;dinger equation, phase shifts, binomial potential function. Academic Journals 2011 TEXT text/html https://academicjournals.org/journal/AJMCSR/article-abstract/5C867A62346 http://dx.doi.org/10.5897/AJMCSR.9000045 en Copyright © 2011 Hemant Kumar and Vimal Pratap Singh
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