ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 9 2 2014 11 1 On Generalized Coprime Graphs 1 6 EN S. Mutharasu Manonmaniam Sundaranar University N. Mohamed Rilwan Manonmaniam Sundaranar University M. K. Angel Jebitha Manonmaniam Sundaranar University T. Tamizh Chelvam Paul Erdos defined the concept of coprime graph and studied about cycles in coprime graphs. In this paper this concept is generalized and a new graph called Generalized coprime graph is introduced. Having observed certain basic properties of the new graph it is proved that the chromatic number and the clique number of some generalized coprime graphs are equal.

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 9 2 2014 11 1 Local Cohomology with Respect to a Cohomologically Complete Intersection Pair of Ideals 7 13 EN A. Pour Eshmanan Talemi A. Tehranian Let $(R,fm,k)$ be a local Gorenstein ring of dimension $n$. Let $H_{I,J}^i(R)$ be the  local cohomology with respect to a pair of ideals $I,J$ and $c$ be the $inf{i|H_{I,J}^i(R)neq0}$. A pair of ideals $I, J$ is called cohomologically complete intersection if $H_{I,J}^i(R)=0$ for all $ineq c$. It is shown that, when $H_{I,J}^i(R)=0$ for all $ineq c$, (i) a minimal injective resolution of $H_{I,J}^c(R)$ presents like that of a Gorenstein ring (ii) $Hom_R(H_{I,J}^c(R),H_{I,J}^c(R))simeq R$, where $(R,fm)$ is a complete ring. Also we get an estimate of the  dimension of $H_{I,J}^i(R)$.

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 9 2 2014 11 1 Strongly almost ideal convergent sequences in a locally convex space defined by Musielak-Orlicz function 15 35 EN B. Hazarika Rajiv Gandhi University In this article, we introduce a new class of ideal convergent sequence spaces using an infinite matrix, Musielak-Orlicz function and a new generalized difference matrix in locally convex spaces. We investigate some linear topological structures and algebraic properties of these spaces. We also give some relations related to these sequence spaces.

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 9 2 2014 11 1 The p-median and p-center Problems on Bipartite Graphs 37 43 EN J. Fathali N. Jafari Rad S. Rahimi Sherbaf Let $G$ be a bipartite graph. In this paper we consider the two kind of location problems namely $p$-center and $p$-median problems on bipartite graphs. The $p$-center and $p$-median problems asks to find a subset of vertices of cardinality $p$, so that respectively the maximum and sum of the distances from this set to all other vertices in $G$ is minimized. For each case we present some properties to find exact solutions.

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 9 2 2014 11 1 Chromaticity of Turan Graphs with At Most Three Edges Deleted 45 64 EN G.-C. Lau Y.-H. Peng S. Alikhani Let $P(G,lambda)$ be the chromatic polynomial of a graph $G$. A graph $G$ ischromatically unique if for any graph $H$, $P(H, lambda) = P(G,lambda)$ implies $H$ is isomorphic to $G$. In this paper, we determine the chromaticity of all Tur;#39{a}n graphs with at most three edges deleted. As a by product, we found many families of chromatically unique graphs and chromatic equivalence classes of graphs.

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 9 2 2014 11 1 A Semidefinite Optimization Approach to Quadratic Fractional Optimization with a Strictly Convex Quadratic Constraint 65 71 EN M. Salahi S. Fallahi In this paper we consider a fractional optimization problem that minimizes the ratio of two quadratic functions subject to a strictly convex quadratic constraint. First using the extension of Charnes-Cooper transformation, an equivalent homogenized quadratic reformulation of the problem is given. Then we show that under certain assumptions, it can be solved to global optimality using semidefinite optimization relaxation in polynomial time.

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 9 2 2014 11 1 On Some Fractional Systems of Difference Equations 73 86 EN N. Touafek Jijel University This paper deal with the solutions of the systems of difference equations $$x_{n+1}=frac{y_{n-3}y_nx_{n-2}}{y_{n-3}x_{n-2}pm y_{n-3}y_n pm y_nx_{n-2}}, ,y_{n+1}=frac{y_{n-2}x_{n-1}}{ 2y_{n-2}pm x_{n-1}},,nin mathbb{N}_{0},$$ where $mathbb{N}_{0}=mathbb{N}cup left{0right}$, and initial values $x_{-2},, x_{-1},,x_{0},,y_{-3},,y_{-2},,y_{-1},,y_{0}$ are non-zero real numbers.

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 9 2 2014 11 1 Some Results on Convexity and Concavity of Multivariate Copulas 87 100 EN A. Dolati A. Dehgan Nezhad This paper provides some results on different types of convexity and concavity in the class of multivariate copulas. We also study their properties and provide several examples to illustrate our results.

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 9 2 2014 11 1 Application of the Norm Estimates for Univalence of Analytic Functions 101 108 EN R. Aghalary By using norm estimates of the pre-Schwarzian derivatives for certain family of analytic functions, we shall give simple sufficient conditions for univalence of analytic functions.

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 9 2 2014 11 1 On the Ultramean Construction 109 119 EN M. Bagheri Tarbiat-Modares We use the ultramean construction to prove linear compactness theorem. We also extend the Rudin-Keisler ordering to maximal probability charges and characterize it by embeddings of power ultrameans.

ACECR at Tarbiat Modares University Iranian Journal of Mathematical Sciences and Informatics 1735-4463 9 2 2014 11 1 ABSTRACTS IN PERSIAN - Vol. 9, No. 2 121 131 EN Name of Authors in This Volume Please see the full text contains the Pesian abstracts for this volume.