eng
Islamic Azad University, Rasht Branch
Iranian Journal of Optimization
2008-5427
2008-5427
2015-01-01
07
1
753
766
526833
A method to obtain the best uniform polynomial approximation for the family of rational function
M. A. Fariborzi Araghi
fariborzi.araghi@gmail.com
1
F. Froozanfar
2
Department of Mathematics, Islamic Azad university, Central Tehran branch
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.
http://ijo.iaurasht.ac.ir/article_526833_88e10aa100f0f18787a31e1a8998c050.pdf
Chebyshev’s polynomials
Chebyshev’s expansion
uniform norm
the best uniform polynomial approximation
alternating set
eng
Islamic Azad University, Rasht Branch
Iranian Journal of Optimization
2008-5427
2008-5427
2015-01-01
07
1
767
773
526834
Exact solutions for wave-like equations by differential transform method
J. Biazar
biazar@guilan.ac.ir
1
M. Eslami
2
Department of Mathematics, Faculty of Sciences, University of Guilan.
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.
http://ijo.iaurasht.ac.ir/article_526834_0831d864cb013f6217f0e66df1b5a423.pdf
Differential transform method
Wave-like equations
eng
Islamic Azad University, Rasht Branch
Iranian Journal of Optimization
2008-5427
2008-5427
2015-01-01
07
1
785
813
526837
AIDS Epidemic Modeling With Different Demographic Structures
Agraj Tripathi
hbti@yahoo.co.in
1
Ram Naresh
2
Department of Mathematics, Bhabha Institute of Technology, Kanpur-209204, India
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.
http://ijo.iaurasht.ac.ir/article_526837_2b44411fe5a169f2fb68b84a6177a425.pdf
HIV/AIDS epidemic
immigration
reproductive number
bifurcation
logistic growth