2019-07-18T16:17:43+04:30 http://ijmsi.ir/browse.php?mag_id=18&slc_lang=en&sid=1
18-319 2019-07-18 10.1002
Iranian Journal of Mathematical Sciences and Informatics IJMSI 1735-4463 2008-9473 7 2014 9 2 On Generalized Coprime Graphs S. Mutharasu skannanmunna@yahoo.com N. Mohamed Rilwan rilwan2020@gmail.com M. K. Angel Jebitha angel_jebitha@yahoo.co.in T. Tamizh Chelvam tamche59@gmail.com 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. Coprime graph Semi-perfect Clique number Chromatic number. 2014 11 01 1 6 http://ijmsi.ir/article-1-319-en.pdf 10.7508/ijmsi.2014.02.001
18-640 2019-07-18 10.1002
Iranian Journal of Mathematical Sciences and Informatics IJMSI 1735-4463 2008-9473 7 2014 9 2 Local Cohomology with Respect to a Cohomologically Complete Intersection Pair of Ideals A. Pour Eshmanan Talemi poureshmanan@iaurasht.ac.ir A. Tehranian tehranian@srbiau.ac.ir 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)\$. Vanishing Local cohomology Gorenstein ring. 2014 11 01 7 13 http://ijmsi.ir/article-1-640-en.pdf 10.7508/ijmsi.2014.02.002
18-522 2019-07-18 10.1002
Iranian Journal of Mathematical Sciences and Informatics IJMSI 1735-4463 2008-9473 7 2014 9 2 Strongly almost ideal convergent sequences in a locally convex space defined by Musielak-Orlicz function B. Hazarika bh_rgu@yahoo.co.in 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. \$I\$-convergence difference space Musielak-Orlicz function. 2014 11 01 15 35 http://ijmsi.ir/article-1-522-en.pdf 10.7508/ijmsi.2014.02.003
18-641 2019-07-18 10.1002
Iranian Journal of Mathematical Sciences and Informatics IJMSI 1735-4463 2008-9473 7 2014 9 2 The p-median and p-center Problems on Bipartite Graphs J. Fathali fathali@shahroodut.ac.ir N. Jafari Rad n.jafarirad@shahroodut.ac.ir S. Rahimi Sherbaf srahimi@shahroodut.ac.ir 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. Location theory \$p\$-median \$p\$-center Bipartite graphs. 2014 11 01 37 43 http://ijmsi.ir/article-1-641-en.pdf 10.7508/ijmsi.2014.02.004
18-642 2019-07-18 10.1002
Iranian Journal of Mathematical Sciences and Informatics IJMSI 1735-4463 2008-9473 7 2014 9 2 Chromaticity of Turan Graphs with At Most Three Edges Deleted G.-C. Lau laugc@johor.uitm.edu.my Y.-H. Peng yhpeng@fsas.upm.edu.my S. Alikhani alikhani@yazd.ac.ir 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'{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. Chromatic polynomial Chromatic uniqueness Turan graph. 2014 11 01 45 64 http://ijmsi.ir/article-1-642-en.pdf 10.7508/ijmsi.2014.02.005
18-643 2019-07-18 10.1002
Iranian Journal of Mathematical Sciences and Informatics IJMSI 1735-4463 2008-9473 7 2014 9 2 A Semidefinite Optimization Approach to Quadratic Fractional Optimization with a Strictly Convex Quadratic Constraint M. Salahi salahim@guilan.ac.ir S. Fallahi saeedf808@gmail.com 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. Quadratic fractional optimization Semidefinite optimization relaxation Global optimization. 2014 11 01 65 71 http://ijmsi.ir/article-1-643-en.pdf 10.7508/ijmsi.2014.02.006
18-524 2019-07-18 10.1002
Iranian Journal of Mathematical Sciences and Informatics IJMSI 1735-4463 2008-9473 7 2014 9 2 On Some Fractional Systems of Difference Equations N. Touafek nouressadat_touafek@yahoo.com 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. System of difference equations Form of the solutions Periodicity. 2014 11 01 73 86 http://ijmsi.ir/article-1-524-en.pdf 10.7508/ijmsi.2014.02.007
18-644 2019-07-18 10.1002
Iranian Journal of Mathematical Sciences and Informatics IJMSI 1735-4463 2008-9473 7 2014 9 2 Some Results on Convexity and Concavity of Multivariate Copulas A. Dolati adolati@yazd.ac.ir A. Dehgan Nezhad anezhad@yazd.ac.ir 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. Componentwise concavity Copula Quasi-concavity Schur-concavity. 2014 11 01 87 100 http://ijmsi.ir/article-1-644-en.pdf 10.7508/ijmsi.2014.02.008
18-377 2019-07-18 10.1002
Iranian Journal of Mathematical Sciences and Informatics IJMSI 1735-4463 2008-9473 7 2014 9 2 Application of the Norm Estimates for Univalence of Analytic Functions 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. Starlike functions Differential subordination Integral operators. 2014 11 01 101 108 http://ijmsi.ir/article-1-377-en.pdf 10.7508/ijmsi.2014.02.009
18-391 2019-07-18 10.1002
Iranian Journal of Mathematical Sciences and Informatics IJMSI 1735-4463 2008-9473 7 2014 9 2 On the Ultramean Construction M. Bagheri bagheri@modares.ac.ir 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. Continuous logic Ultramean Linear compactness Rudin-Keisler ordering. 2014 11 01 109 119 http://ijmsi.ir/article-1-391-en.pdf 10.7508/ijmsi.2014.02.010
18-843 2019-07-18 10.1002
Iranian Journal of Mathematical Sciences and Informatics IJMSI 1735-4463 2008-9473 7 2014 9 2 ABSTRACTS IN PERSIAN - Vol. 9, No. 2 Name of Authors in This Volume Please see the full text contains the Pesian abstracts for this volume. 2014 11 01 121 131 http://ijmsi.ir/article-1-843-en.pdf