Islamic Azad University, Rasht Branch
Iranian Journal of Optimization
2008-5427
07
1
2015
01
01
A method to obtain the best uniform polynomial approximation for the family of rational function
753
766
EN
M. A.
Fariborzi Araghi
Department of Mathematics, Islamic Azad university, Central Tehran branch
fariborzi.araghi@gmail.com
F.
Froozanfar
Ms.student of Mathematics, Islamic Azad university, Kermanshah branch, Kermanshah, Iran
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 b2-4ac L 0 and b2-4ac G 0.
Chebyshev’s polynomials,Chebyshev’s expansion,uniform norm,the best uniform polynomial approximation,alternating set
http://ijo.iaurasht.ac.ir/article_526833.html
http://ijo.iaurasht.ac.ir/article_526833_88e10aa100f0f18787a31e1a8998c050.pdf
Islamic Azad University, Rasht Branch
Iranian Journal of Optimization
2008-5427
07
1
2015
01
01
Exact solutions for wave-like equations by differential transform method
767
773
EN
J.
Biazar
Department of Mathematics, Faculty of Sciences, University of Guilan.
biazar@guilan.ac.ir
M.
Eslami
Department of Mathematics, Faculty of Sciences, University of Guilan.
Differential transform method has been applied to solve many functional equations so far. In this article, we have used this method to solve wave-like 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.
Differential transform method,Wave-like equations
http://ijo.iaurasht.ac.ir/article_526834.html
http://ijo.iaurasht.ac.ir/article_526834_0831d864cb013f6217f0e66df1b5a423.pdf
Islamic Azad University, Rasht Branch
Iranian Journal of Optimization
2008-5427
07
1
2015
01
01
AIDS Epidemic Modeling With Different Demographic Structures
785
813
EN
Agraj
Tripathi
Department of Mathematics, Bhabha Institute of Technology,
Kanpur-209204, India
hbti@yahoo.co.in
Ram
Naresh
Department of Mathematics, Harcourt Butler Technological Institute,
Kanpur-208002, India
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.
HIV/AIDS epidemic,immigration,reproductive number,bifurcation,logistic growth
http://ijo.iaurasht.ac.ir/article_526837.html
http://ijo.iaurasht.ac.ir/article_526837_2b44411fe5a169f2fb68b84a6177a425.pdf