African Journal of
Mathematics and Computer Science Research

  • Abbreviation: Afr. J. Math. Comput. Sci. Res.
  • Language: English
  • ISSN: 2006-9731
  • DOI: 10.5897/AJMCSR
  • Start Year: 2008
  • Published Articles: 245

AJMCSR Articles

Investigation on the effect of stent in unsteady blood flow

February 2012

  In this work, we tried to determine the fact that an interest in optimal stents shapes helps to minimize fluid swirl and to maximize shear stress on the wall artery in order to reduce the risk of the restenosis in stented segments. Our study deals with three geometric parameters of the stent, namely the strut spacing, the strut height and the strut width. These parameters have direct effect on blood...

Author(s): Ibrahima Mbaye

Thermal deflection of a thin circular plate with radiation

February 2012

  This paper deals with the determination of thermal deflection of a thin circular plate defined as ;. A circular plate is considered having arbitrary initial temperature and subjected to radiation type boundary condition which is fixed at . The non homogeneous type boundary conditions are maintained at plane surfaces of the plate. The governing heat conduction equation has been solved by using...

Author(s): Hamna Parveen, N. K. Lamba and N. W. Khobragade

Application of Bousinesq’s and Westergaard’s formulae in analysing foundation stress distribution for a failed telecommunication mast

February 2012

  The concurrent foundation failure of telecommunication masts in Nigeria and all over the world which endanger the lives and properties of residents situated within the fall distance of the telecommunication mast is a thing of great concern. In this study, a GSM mast that underwent foundation failure at Ibadan, Oyo State, Nigeria was critically examined with a view to providing engineering solution. The soil...

Author(s): OJEDOKUN Olalekan Yinka and OLUTOGE Festus Adeyemi

Utilization of mixture of andin imputation for missing data in post-stratification

February 2012

  To estimate the population mean using auxiliary variable there are many estimators available in literature like-ratio, product, regression, dual-to-ratio estimator and so on. Suppose that all the information of the main variable is present in the sample but only a part of data of the auxiliary variable is available. Then, in this case none of the aforementioned estimators could be used. This paper presents an...

Author(s): D. Shukla, D. S. Thakur and N. S. Thakur

Critical thinking: Essence for teaching mathematics and mathematics problem solving skills

February 2012

  Critical thinking is a learned skill that requires instruction and practice. Mathematics education instructors at both the secondary and post-secondary levels can enhance students’ critical thinking skills by (i) using instructional strategies that actively engage students in the learning process rather than relying on lecture and note memorization, (ii) focusing instruction on the process of learning...

Author(s): Ebiendele Ebosele Peter

Einstein's equivalence principle has three further implications besides affecting time: T-L-M-Ch theorem (“Telemach”)

February 2012

  General relativity is notoriously difficult to interpret. A "return to the mothers" is proposed to better understand the gothic-R theorem of the Schwarzschild metric of general relativity. It is shown that the new finding is already implicit in Einstein's equivalence principle of 1907 and hence in special relativity (with acceleration included). The TeLeMaCh theorem, named onomatopoetically...

Author(s): Otto E. Rossler

Cross efficiency by using common weights for fuzzy data

February 2012

  This paper firstly revists the cross efficiency evaluation method which is an extention tool of data envelopment analysis (DEA), then analyzes the potential flawes which happens when the ultimate average cross efficiency scores are used. In this paper, we consider the decision making units (DMUs) as the players in a cooperative fuzzy game, where the characteristic function values of coalitions are...

Author(s): Sahand Daneshvar, Mojtaba Ramezani, Mozhgan Mansouri Kaleibar and Sharmin Rahmatfam

Flow induced by non-coaxial rotations of porous disk and a fluid in a porous medium

January 2012

  This paper deals with the flow of an incompressible, viscous and electrically conducting fluid in a porous medium when no slip condition is no longer valid. The fluid is bounded by a non-conducting porous disk. The flow is due to non-coaxial rotations of porous disk and a fluid at infinity. The fluid is electrically conducting in the presence of a constant applied magnetic field in the transverse direction....

Author(s): I. Ahmad

A study on a novel method of mining fuzzy association using fuzzy correlation analysis

January 2012

  Two different data variables may behave very similarly. Correlation is the problem of determining how much alike the two variables actually are and association rules are used just to show the relationships between data items. Mining fuzzy association rules is the job of finding the fuzzy item-sets which frequently occur together in large fuzzy data set, where the presence of one fuzzy item-set in a record...

Author(s): Karthikeyan T., Samuel Chellathurai A. and Praburaj B.

A sampling plan with producer’s allowable risk (PAR) at maximum allowable proportion defective (MAPD)

January 2012

  This paper deals with sampling designs on incoming quality MAPD along with a specified probability of acceptance at this point called producer’s allowable risk (PAR). It is defined as the minimum probability of acceptance of the lot with a maximum allowable proportion defective. Tables and graphs are presented, comparing the efficiency of new SSP as to protect AQL. An optimum criterion of sample size...

Author(s): T. B. Ramkumar

Wu’s algorithm and its possible application in cryptanalysis

January 2012

  In this paper we reviewed Wu’s algorithm and introduced it as a cryptanalysis technique. This study reveals that when Wu’s algorithm is used for cryptanalysis it simplifies. This is true because Wu’s algorithm has to be applied to binary polynomials only, when used for cryptanalysis. To summarize, we gave a full description of Wu’s algorithm in the binary case and also a...

Author(s):   T. L. Grobler, A. J. van Zyl, J. C. Olivier, W. Kleynhans, B. P. Salmon, and W. T. Penzhorn

Egoists dilemma with fuzzy data

January 2012

  In this paper, we investigate the problems of consensus–making among individuals or organizations with multiple criteria for evaluating performance when the players are supposed to be egoistic and the score for each criterion for a player is supposed to be fuzzy number. We deal with problems with fuzzy parameters from the viewpoint of experts’ imprecise or fuzzy understanding of the...

Author(s): Sahand Daneshvar, Mozhgan Mansouri Kaleibar and Mojtaba Ramezani

On three-dimensional generalized sasakian space – forms

January 2012

  The object of the present paper is to study locally j –symmetric three-dimensional generalized Sasakian space forms and such manifolds with Ricci semi symmetric, h -parallel Ricci tensor and cyclic Ricci tensor. Such space forms with non-null concircular vector field are also considered. Key words: Generalized sasakian space forms, cosymplectic, locally-j -symmetric, h -parallel ricci...

Author(s): S. Yadav and D. L. Suthar

Department of Applied Mathematics with Oceanology and Computer Programming, Vidyasagar University, Midnapore -- 721102, India

December 2011

  In this paper, soft matrices are defined based on soft set. Cartesian product of two soft sets is defined here. The very common operations of soft matrices are defined like AND, OR, union, intersection. commutative, associative, distributive, De Morgan's laws and convergent property for soft matrices are investigated.   Key words:  Soft set, soft relation, soft matrices, AND, OR...

Author(s): Sanjib Mondal and Madhumangal Pal

  • Article Number: A9EF6D33112

Estimation of temperature distribution and thermal stresses in a thick circular plate

December 2011

  A thick circular plate with the arbitrary initial heat flux prescribed on the upper surface is considered and lower and the curved boundary surface are kept at zero temperature. The temperature distribution in the plate is determined by solving heat conduction equation with the help of variable separation technique and then stresses are determined with the help of suitable Michell’s...

Author(s): G. D. Kedar and K. C. Deshmukh

  • Article Number: 0BE3D6E3128

Sharon - Agent based service middleware for E-governance: A systematic web examination based approach using Christina ontology

December 2011

  Over the past few years, semantic web service and multi agent approach has been used successfully inthe development of E-governance. Such a hybrid approach can be considered as an effective approachfor the development of predictive modeling in complex...

Author(s):   T. Shantha Kumar    

  • Article Number: D28DD1B3140

Some common fixed point theorems in D* - metric space

November 2011

  In this paper we establish some common fixed point theorems for contraction and generalized contraction mappings in D* - metric space which is introduced by Shaban et al. (2007). In what follows, (X, D*) will denote D* - metric space, N, the set of all natural number and R+, the set of all positive real numbers.   Key words: D* - metric contractive mapping, complete D* - metric space, common...

Author(s): Veerapandi T. and Aji M. Pillai

  • Article Number: 0CF557D3039

Formal partitioning analysis and verification of extended algebraic automata

November 2011

Algebraic automata is getting much importance in theoretical computer science because of its various applications, for example, in optimization of programs, verification of protocols, cryptography and modeling biological phenomena. Design of a complex system not only requires functionality but it also needs to capture its control behaviour. This paper is a part of our ongoing research on integration of algebraic...

Author(s): Nazir Ahmad Zafar

  • Article Number: DCEC7CB3065

Entropy and utility based trip distribution model

November 2011

  This paper aims to explore the interrelation and equivalence between methods of maximum entropy and utility in establishing the trip distribution model.   Key words: Entropy, utility, trip distribution, Bose–Einstein entropy, Fermi-Dirac entropy.

Author(s): R. Kar and S. K. Mazumder

  • Article Number: 6A267B83073

Solving traveling salesman problem by using a fuzzy multi-objective linear programming

October 2011

  The traveling salesman problem (TSP) is one of the most intensively studied problems in computational mathematics. Information about real life systems is often available in the form of vague descriptions. Hence, fuzzy methods are designed to handle vague terms, and are most suited to finding optimal solutions to problems with vague parameters. This study develops a fuzzy multi-objective linear programming...

Author(s): Sepideh Fereidouni

  • Article Number: 0E978602988

Optimizing the underground water confined steady flow using a fuzzy approach

October 2011

  In this paper we discuss the underground water aquifers, the confined steady flow in homogeneous system where the transmissivities at all nodes inside the zone are represented by the same fuzzy number. A solution algorithm to solve the underground water confined steady flow in homogeneous system (in three dimensions) under fuzziness is considered. The purpose behind this study is to optimize the sum of the...

Author(s): Omar M. Saad, Bayoumi M. Ali Hassan and Ibrahim M. Hizam

  • Article Number: 3E26B383004

Characterization of de Bruijn graphs homomorphisms

September 2011

  We study homomorphisms between de Bruijn digraphs of different orders. A main theme of this paper is to characterize de Bruijn graph homomorphisms such that the inverse of a factor in the lower order digraph is also a factor in the higher order one, where a factor is a collection of cycles that partition the digraph. We generalize Lempel's homomorphism by describing and characterizing a class of...

Author(s): Akinwande Mufutau Babatunde O.

  • Article Number: 7CBE2102839

On weakly symmetric and weakly Ricci symmetric Lorentzian Para-Sasakian manifolds

September 2011

  The aim of the present paper is to study weakly symmetric and weakly Ricci symmetric an LP-Sasakian manifolds and proved that if weakly symmetric LP-Sasakian manifold satisfies -parallel Ricci condition then the scalar curvature of the manifolds is equal to rank of . If weakly symmetric an LP-Sasakian manifolds satisfies Ricci tensor of coddazi type then the manifolds is R-Harmonic, further we have...

Author(s): Dhruwa Narain and Sunil Yadav

  • Article Number: 5B730182856

Conceptual networks: The role of concept lattices in knowledge management

September 2011

Concepts are defined as couples (O, A) of sets O and A: the object O (a set of none, or one or more elements) is assigned to the set A of these elements’ (common) attributes. The objects change according to the sequence of attributes. Only couples of objects and attributes, that is concepts, are adequate for our world. The connections and links we need in databases and multimedia are expressed, naturally, by...

Author(s):   Megaklis Th. Sotiropoulos

  • Article Number: B4B49A02870

Optimality of the flexible job shop scheduling problem

September 2011

  The flexible job shop scheduling problem is NP-hard problem. There is no efficient technique to check the optimality of the solution of the flexible job shop scheduling problem. So, in this paper, theorems and lemmas for defining some optimality conditions for the solution of the flexible job shop scheduling problem are introduced. In addition, a mathematical model of the primal problem of the flexible job...

Author(s): Abd Elazeem Mohamed Abd Elazeem, Mohamed Sayed Ali Osman and Mohamed Bayoumi Ali Hassan

  • Article Number: F4E212C2890

Interpolation by quartic splines

September 2011

  This paper proposes two special lacunary interpolation problems using quartic splines of continuity class C2. We call the problems (0,3) and (0,4) lacunary interpolation. In these two cases, the third and fourth derivative respectively is also prescribed in between the nodes along with the function value at the nodes. This paper is divided into two parts namely cases A and B. Case A deals with the (0,3)...

Author(s): Kulbhushan Singh

  • Article Number: A34D2C42919

Thermal stresses induced by a point heat source in a hollow disk by quasi-static approach

September 2011

  This paper deals with the two dimensional non-homogeneous boundary value problem of heat conduction in a hollow disk defined as  and discussed the thermoelastic behavior due to internal heat generation within it. A thin hollow disk is considered having arbitrary initial temperature and subjected to time dependent heat flux at the outer circular boundary  whereas inner circular...

Author(s): K. C. Deshmukh, Y. I. Quazi and S. D. Warbhe

  • Article Number: 53D48132934

New scrambling algorithm for hiding scanned documents

September 2011

  This paper introduces a new technique to hide scanned document in a digital image. It is a one-to-one matching between the pixels from the cover image to the pixel in scanned documents image. The proposed algorithm is an efficient computer-based steganographic method for embedding secret messages into images without producing noticeable changes is implemented. There is no need of referencing the original...

Author(s): Mohamed Mostafa AbdAllah, and Gasim Alandjani

  • Article Number: 0DBC92C2634

Projective semimodules

September 2011

  In this paper, a natural dual of an injective semimodule which was obtained by reversing the arrows in the definition of injective semimodule and replacing epimorphsims with monomorphisms was considered. These new objects are called “projective semimodules”.   Key words: Projective semimodule, epimorphisim, left regular exact sequence, proper exact sequence.

Author(s): Huda Mohammed J. Al-Thani

  • Article Number: 6456B632644

A common fixed point theorem and some fixed point theorems in D*- Metric spaces

August 2011

  In this paper we establish some common fixed point theorems for contraction and some generalized contraction mappings in D* - metric space which is introduced by Shaban et al. (2007). In what follows, (X, D*) will denote D* - metric space, N is the set of all natural number and R+ is the set of all positive real number.   Key words: D*- metric, contraction mapping, complete D*- metric...

Author(s): T. Veerapandi and Aji .M. Pillai

  • Article Number: E596C022612

Some finite integrals involving multivariable polynomials, H-function of one variable and H-function of ‘r’ variables

August 2011

  In the present paper we establish the integrals involving the product of two general classes of polynomial, H-function of one variable and H-function of ‘r’ variables.  These integrals are unified in nature and we can derive from them by a large number of integrals involving simpler functions and polynomials as their particular cases.   Key...

Author(s): B. Satyanarayana and Y. Pragathi Kumar

  • Article Number: ACCE9CD2620

MHD Heat transfer aspects between two parallel conducting porous walls in a rotating system, with Hall currents

July 2011

  An analysis is presented for heat transfer in fully developed viscous incompressible hydromagnetic flow of an ionized gas bounded by two parallel porous walls under the action of uniform transverse magnetic field, when rotated with an angular velocity about an axis perpendicular to the walls, by taking Hall effect into account. The governing equations of motion and heat transfer expressing the physical...

Author(s): T. Linga Raju and P. S. R. Murty

  • Article Number: DFF5D512543

Mixed type symmetric and self duality for multiobjective variational problems with support functions

July 2011

  In this paper, a pair of mixed type symmetric dual multiobjective variational problems containing support functions is formulated. This mixed formulation unifies two existing pairs Wolfe and Mond-Weir type symmetric dual multiobjective variational problems containing support functions. For this pair of mixed type nondifferentiable multiobjective variational problems, various duality theorems are established...

Author(s): Iqbal Husain and Rumana G. Mattoo

  • Article Number: 0ED02D42548

A Branch and Bound approach to a state government capital budgeting

July 2011

  The capital budgeting problem is a multi-constraint Knapsack problem. Hence this paper provides a solution to a capital budgeting problem of Akwa Ibom State, Nigeria using a Branch and Bound approach. The capital projects are summarized in four broad groups: The Economic sector (X1), The Social Service sector (X2), The Environmental/Regional Development sector (X3), and...

Author(s): N. P. Akpan, E. H. Etuk and I. D. Essi

  • Article Number: D6B92F52559

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...

Author(s):

  • Article Number: BA910612563

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,...

Author(s): Kenekayoro Patrick T.

  • Article Number: 88593D92458

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...

Author(s): Stephen Agyepong, Michael Franklin Bosu and James Ben Hayfron-Acquah

  • Article Number: 1FE3E0E2481

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...

Author(s): Nirmeen A. Bahnasawy, Magdy A. Koutb, Mervat Mosa and Fatma Omara

  • Article Number: 5D5E6C72517

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...

Author(s): Satyanarayana Bhavanari, Godloza Lungisile and Nagaraju Dasari

  • Article Number: 727C6A02532

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.

Author(s): Zhang Xiong and Huang Lihang

  • Article Number: 4BE50002405

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...

Author(s): Shashi Kant, Deepak Kumar and Sanjeev Kumar

  • Article Number: 1D42C902396

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.

Author(s): S. K. Paikray, U. K. Misra and N. C. Sahoo

  • Article Number: 8E33BAE2325

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...

Author(s): Hemant Kumar and Vimal Pratap Singh

  • Article Number: 5C867A62346

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.

Author(s): Ahmed Himadan Ahmed and Shawgy Hussein

  • Article Number: 32C8E452365

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,...

Author(s): Amal Kumar Adak and Monoranjan Bhowmik

  • Article Number: 31179E12373

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...

Author(s): Peasah O. K., Amponsah S. K. and Asamoah D.

  • Article Number: 84A238D39964

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....

Author(s): S. J. Kayode

  • Article Number: 82F8EB61723

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...

Author(s): Mohammad Saeed Zaeri, Amir Sadeghi, Amir Naderi, Abolfazl Kalanaki Reza Fasihy, Seyed Masoud Hosseini Shorshani, and Arezou Poyan

  • Article Number: 09C41A91731

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...

Author(s): S. K. Amponsah, K. F. Darkwah and F. K. Awuah

  • Article Number: 7063CC62149

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...

Author(s): Kenekayoro Patrick T.

  • Article Number: 37D10622168

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