2015
7
1
1
61
A method to obtain the best uniform polynomial approximation for the family of rational function
2
2
In this article, by using Chebyshev’s polynomials and Chebyshev’s expansion, we obtain the best uniform polynomial approximation out of P2n to a class of rational functions of the form (ax2+c)1 on any non symmetric interval [d,e]. Using the obtained approximation, we provide the best uniform polynomial approximation to a class of rational functions of the form (ax2+bx+c)1 for both cases b24ac L 0 and b24ac G 0.
1

753
766


M. A.
Fariborzi Araghi
Department of Mathematics, Islamic Azad university, Central Tehran branch
Department of Mathematics, Islamic Azad university
Iran
fariborzi.araghi@gmail.com


F.
Froozanfar
Ms.student of Mathematics, Islamic Azad university, Kermanshah branch, Kermanshah, Iran
Ms.student of Mathematics, Islamic Azad university
Iran
Chebyshev’s polynomials
Chebyshev’s expansion
uniform norm
the best uniform polynomial approximation
alternating set
Exact solutions for wavelike equations by differential transform method
2
2
Differential transform method has been applied to solve many functional equations so far. In this article, we have used this method to solve wavelike equations. Differential transform method is capable of reducing the size of computational work. Exact solutions can also be achieved by the known forms of the series solutions. Some examples are prepared to show theefficiency and simplicity of the method.
1

767
773


J.
Biazar
Department of Mathematics, Faculty of Sciences, University of Guilan.
Department of Mathematics, Faculty of Sciences,
Iran
biazar@guilan.ac.ir


M.
Eslami
Department of Mathematics, Faculty of Sciences, University of Guilan.
Department of Mathematics, Faculty of Sciences,
Iran
Differential transform method
Wavelike equations
AIDS Epidemic Modeling With Different Demographic Structures
2
2
The most urgent public health problem today is to devise effective strategies to minimize the destruction caused by the AIDS epidemic. Mathematical models based on the underlying transmission mechanisms of the AIDS virus can help the medical/scientific community understand and anticipate its spread in different populations and evaluate the potential effectiveness of different approaches for bringing the epidemic under control. In this paper, we present the framework of conventional compartmental models for the spread of HIV infection to investigate the effect of various types of growths of host population. The model presented has been studied qualitatively using stability theory of differential equations. The equilibrium and stability analysis have been carried out by establishing local and global stability results and some inferences have been drawn to understand the spread of the disease. A numerical study in each case is also performed to see the influence of certain parameters on the disease spread and to support the analytical results. The model analysis has also been applied to compare the theoretical results with the known Indian HIV data.
1

785
813


Agraj
Tripathi
Department of Mathematics, Bhabha Institute of Technology,
Kanpur209204, India
Department of Mathematics, Bhabha Institute
India
hbti@yahoo.co.in


Ram
Naresh
Department of Mathematics, Harcourt Butler Technological Institute,
Kanpur208002, India
Department of Mathematics, Harcourt Butler
India
HIV/AIDS epidemic
Immigration
reproductive number
bifurcation
logistic growth