4th-Step implicit formula for solution of initial value problems of second order ordinary differential equations
July 2011
This paper proposes a direct method of solution for second order initial value problems of ordinary differential equations. Its derivation adopts Taylor series expansion techniques and Dahlquist stability test model. It was revealed from the results obtained that the method is consistent, convergent and zero-stable. Numerical examples are solved to ensure accuracy of the method on both linear and non-linear...
One way functions and public key cryptography
June 2011
The problem faced with symmetric ciphers has always been key exchange. Hellman and Diffie (1976) proposed the idea for key exchange (public key cryptography). Their idea was based on the difficulty in inverting certain mathematical functions; one way functions. The RSA was one of the first practical solutions of key exchange. This paper identifies one way functions and their corresponding public key encryption system,...
The formulation of complex queries and interactions using SMS text messages
June 2011
There is no question that short message service (SMS) has achieved huge success in the wireless world. Billions of SMS text messages are sent every day worldwide. SMS is now a major revenue generator for wireless carriers like expresso and MTN of Ghana. A lot of innovative applications are now built on top of the SMS technology and more are being developed. One of the emerging applications is the use of text...
A new algorithm for static task scheduling for heterogeneous distributed computing systems
June 2011
Effective task scheduling is essential for obtaining high performance in heterogeneous distributed computing systems (HeDCSs). However, finding an effective task scheduling in HeDCSs should take into consideration the heterogeneity of processors and inter-processor communication over head, which results from non-trivial data movement between tasks scheduled on different processors. In this paper, a new high...
Some results on principal ideal graph of a ring
June 2011
Let R be an associative (not necessarily commutative) ring. In the present paper, we introduced a new type of graph (called ‘Principal Ideal Graph’, denoted by PIG(R)) related to a given associative ring R. We presented some examples. We obtained few fundamental important relations between rings and graphs with respect to the properties: simple ring, complete graph, etc. We also observed...
Asymptotic behavior of solutions of nonlinear delay differential equations with impulse
May 2011
This paper studies the asymptotic behavior of solutions of the second-order nonlinear delay differential equations with impulses: and some sufficient conditions are obtained. Key words: Asymptotic behavior, second-order nonlinear delay differential equation, impulses.
Mathematical model of homogenious tumour growth with delay in time
May 2011
This paper consist of a problem of tumor growth with the function of phosphorous to both tumor cells and healthy cells. A detailed discussion about the growth of healthy cells and tumor cells was observed here. A consideration about the solution part of tumor micro vessels has been made here. The governing equations are than solved using MATLAB (a differential equation solver) and graphs are drawn which show...
Triangular matrix summability of a series
April 2011
In this paper, in extending a result of Savas and Rhodes on indexed matrix summability, an analogue theorem has been established by using Euler-Totient function. Key words: Summability, triangular matrix summability, Euler-Totient function.
Approximation formulae for phase shifts of s–wave Schrödinger equation due to binomial potential and their applications
April 2011
In this paper, we derive the approximation formulae for phase shifts of s-wave Schrödinger 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...
Estimates for contraction oscillatory integral operators on Lp – spaces
April 2011
In this study, we shall prove that the oscillatory integral operator can be reduced to the study of another contraction oscillatory integral operator, with a fixed point which leads to a sharp estimate. Key words: Oscillatory integrals operator, bilinear forms, Fourier transform, non singular matrix, intertwining.
Interval cut-set of interval-valued intuitionistic fuzzy sets
April 2011
In this paper, different types of interval cut-set of interval-valued intuitionistic fuzzy sets (IVIFSs), complement of these cut-sets are defined. Some properties of those cut-set of IVIFSs are investigated. Also three decomposition theorems of IVIFSs are defined. These works can also be used in setting up the basic theory of IVIFSs. Key words: Interval-valued intuitionistic fuzzy sets,...
Knapsack problem: A case study of garden city radio (GCR), Kumasi, Ghana
April 2011
Packing or arrangement problems form an integral part in a man’s life and cannot be out rightly ignored. Items need to be well arranged and protected to survive the move unscathed. When it is done efficiently, at least to its optimal level, space is saved. A room may become spacious when furniture, bags and other household items are arranged very well. The end result is beauty and attractiveness. Radio...
A class of one-point zero-stable continuous hybrid methods for direct solution of second-order differential equations
March 2011
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....
Application of multi criteria decision making technique to evaluation suppliers in supply chain management
March 2011
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...
Optimal packing of fm station progammes case study: Kaase Fm Station, Kumasi, Ghana
March 2011
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...
Semantic web - The future of the web
March 2011
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...
Some inequalities of a formula of population size due to epidemics model problem
March 2011
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...
A comparative study of a class of implicit multi-derivative methods for numerical solution of non-stiff and stiff first order ordinary differential equations
March 2011
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...
Nonlinear analysis of a fractional reaction diffusion model for tumour invasion
March 2011
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...
On best 1:1 codes for generalized quantitative-qualitative measure of inaccuracy
March 2011
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...
Evaluation of continuous host-parasitoid models
February 2011
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...
Department of Computer Science, University of Peshawar, Peshawar, Khyber Pakhtoonkhwa, Pakistan.
February 2011
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...
Fuzzy multi-objective linear programming for traveling salesman problem
February 2011
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...
Transmission dynamics of infectious diseases by immigrants in a vaccinated and temporary immune protected population
February 2011
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...
Ample invertible sheaves on the irreducible components of an exceptional locus
January 2011
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's Criterion Kleiman (1966). Key words: Simple singularity, exceptional locus, ample sheaves.
A mathematical approach to transportation related data of South Assam for the optimal age of replacement of a vehicle and daily expenditure minimization
January 2011
This paper deals with the replacement issue of an Omni bus plying on Silchar–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...
Location of ambulance emergency medical service in the Kumasi Metropolis, Ghana
January 2011
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...
Modified extended median test
January 2011
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...
Testing the equality of central tendency measures using various trimming strategies
January 2011
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,...
Key exchange scheme with higher security and its analysis
December 2010
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...
A dynamic programming approach to optimal manpower recruitment and promotion policies for the two grade system
December 2010
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...
Performance analysis of QoS in PMP mode WiMAX networks
December 2010
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...
A metaheuristic and PTAS approach for NP-hard scheduling problem with controllable processing times
December 2010
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...
Application of factor analysis to data on improved cassava varieties cultivated in Nigeria
November 2010
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 <...
Consistent estimators of intrinsically linear econometric model of the Nigerian economy
November 2010
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...
A note on indirect least squares and matrix partitioning
November 2010
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...
A study on Agile Software Testing: Emergence and techniques
November 2010
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....
Combined influence of Soret and Dufour effects on convective heat and mass transfer flow through a porous medium in cylindrical annulus with heat sources
October 2010
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...
Transformation of emotion based on acoustic features of intonation patterns for Hindi speech
October 2010
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...
On Laguerre-Gaussians and Fredholm integral equations
October 2010
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...
Exploring Bayesian networks for medical decision support in breast cancer detection
October 2010
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...
An inventory model with price breaks: Fuzzy approach
October 2010
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...
The data encryption standard thirty four years later: An overview
October 2010
The data encryption standard was the first encryption system to meet the National Institute of Standards and Technology’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...
Some properties of upper fuzzy order
September 2010
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.
Minimal strongly balanced changeover designs with first residuals
September 2010
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...
On Monte Carlo forecast of production using nonlinear econometric models
September 2010
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.
Calculation of the electron drift mobility in Cr2+:ZnS and Cr2+:ZnSe materials by rode iteration model
September 2010
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...
Analytical model for I-V analysis of buried gate MESFET with modulation frequency characteristics
September 2010
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...
On discussion of the definition of probability
September 2010
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...
An adaptive finite volume method using thin plate splines for the numerical simulation of the inviscid Burgers’ equation
August 2010
Thin plate splines are utilized in the construction of a non-oscillatory finite volume method for the inviscid Burgers’ 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...
Page 4 of 6, showing 50 records out of 261 total, starting on record 151, ending on 200
Advertisement
Advertisement
