@article {
author = {Jafarpour, M. and Alizadeh, F.},
title = {ASSOCIATED (SEMI)HYPERGROUPS FROM DUPLEXES},
journal = {Journal of Algebraic Systems},
volume = {2},
number = {2},
pages = {83-96},
year = {2015},
publisher = {Shahrood University of Technology},
issn = {2345-5128},
eissn = {2345-511X},
doi = {10.22044/jas.2015.358},
abstract = {In this paper using strongly duplexes we introduce a new class of (semi)hypergroups. The associated (semi)hypergroup from a strongly duplex is called duplex (semi)hypergroup. Two computer programs written in MATLAB show that the two groups $Z_{2n}$ and $Z_{n}times Z_{2}$ produce a strongly duplex and its associated hypergroup is a complementary feasible hypergroup.},
keywords = {Duplexes,semihypergroups,complementary feasible (semi)hypergroups},
url = {http://jas.shahroodut.ac.ir/article_358.html},
eprint = {http://jas.shahroodut.ac.ir/article_358_f99c12fe0b879e885797880dc7afd9b4.pdf}
}
@article {
author = {Alikhani, S. and Jahari, S.},
title = {ON THE EDGE COVER POLYNOMIAL OF CERTAIN GRAPHS},
journal = {Journal of Algebraic Systems},
volume = {2},
number = {2},
pages = {97-108},
year = {2015},
publisher = {Shahrood University of Technology},
issn = {2345-5128},
eissn = {2345-511X},
doi = {10.22044/jas.2015.359},
abstract = {Let $G$ be a simple graph of order $n$ and size $m$. The edge covering of $G$ is a set of edges such that every vertex of $G$ is incident to at least one edge of the set. The edge cover polynomial of $G$ is the polynomial$E(G,x)=sum_{i=rho(G)}^{m} e(G,i) x^{i}$, where $e(G,i)$ is the number of edge coverings of $G$ of size $i$, and$rho(G)$ is the edge covering number of $G$. In this paper we study the edge cover polynomials of cubic graphs of order $10$. We show that all cubic graphs of order $10$ (especially the Petersen graph) are determined uniquely by their edge cover polynomials.},
keywords = {Edge cover polynomial,edge covering,equivalence class,cubic graph,corona},
url = {http://jas.shahroodut.ac.ir/article_359.html},
eprint = {http://jas.shahroodut.ac.ir/article_359_03bd853b0f975a60d986af404d928abd.pdf}
}
@article {
author = {Habibi, M.},
title = {ON ANNIHILATOR PROPERTIES OF INVERSE SKEW POWER SERIES RINGS},
journal = {Journal of Algebraic Systems},
volume = {2},
number = {2},
pages = {109-124},
year = {2015},
publisher = {Shahrood University of Technology},
issn = {2345-5128},
eissn = {2345-511X},
doi = {10.22044/jas.2015.360},
abstract = {Let $alpha$ be an automorphism of a ring $R$. The authors [On skew inverse Laurent-serieswise Armendariz rings, Comm. Algebra 40(1) (2012) 138-156] applied the concept of Armendariz rings to inverse skew Laurent series rings and introduced skew inverse Laurent-serieswise Armendariz rings. In this article, we study on aspecial type of these rings and introduce strongly Armendariz rings of inverse skew power series type. We determine the radicals of the inverse skew Laurent series ring $R((x^{-1};alpha))$, in terms of those of $R$. We also prove that several properties transfer between $R$ and the inverse skew Laurent series extension $R((x^{-1};alpha))$, in case $R$ is a strongly Armendariz ring of inverse skew power series type.},
keywords = {Inverse skew power series extensions,Radical property,Semicommutative rings},
url = {http://jas.shahroodut.ac.ir/article_360.html},
eprint = {http://jas.shahroodut.ac.ir/article_360_3c473d1d286abc25947c292a6b305359.pdf}
}
@article {
author = {Esmaeelnezhad, A.},
title = {COHEN-MACAULAY HOMOLOGICAL DIMENSIONS WITH RESPECT TO AMALGAMATED DUPLICATION},
journal = {Journal of Algebraic Systems},
volume = {2},
number = {2},
pages = {125-135},
year = {2015},
publisher = {Shahrood University of Technology},
issn = {2345-5128},
eissn = {2345-511X},
doi = {10.22044/jas.2015.361},
abstract = {In this paper we use "ring changed'' Gorenstein homological dimensions to define Cohen-Macaulay injective, projective and flat dimensions. For doing this we use the amalgamated duplication of the base ring with semi-dualizing ideals. Among other results, we prove that finiteness of these new dimensions characterizes Cohen-Macaulay rings with dualizing ideals.},
keywords = {Semi-dualizing ideal,Amalgamated duplication,Gorenstein homological dimension,Cohen-Macaulay homological dimension},
url = {http://jas.shahroodut.ac.ir/article_361.html},
eprint = {http://jas.shahroodut.ac.ir/article_361_50a50dd113314eebf1bad604ed0e91b0.pdf}
}
@article {
author = {Moghaddasi, Gh.},
title = {COGENERATOR AND SUBDIRECTLY IRREDUCIBLE IN THE CATEGORY OF S-POSETS},
journal = {Journal of Algebraic Systems},
volume = {2},
number = {2},
pages = {137-146},
year = {2015},
publisher = {Shahrood University of Technology},
issn = {2345-5128},
eissn = {2345-511X},
doi = {10.22044/jas.2015.371},
abstract = {In this paper we study the notions of cogenerator and subdirectly irreducible in the category of S-poset. First we give somenecessary and sufficient conditions for a cogenerator $S$-posets. Then we see that under some conditions, regular injectivity implies generator and cogenerator. Recalling Birkhoff's Representation Theorem for algebra, we study subdirectly irreducible S-posets and give this theorem for the category of ordered right acts over an ordered monoid. Among other things, we give the relations between cogenerators and subdirectly irreducible S-posets.},
keywords = {S-poset,cogenerator,regular injective,subdirectly irreducible},
url = {http://jas.shahroodut.ac.ir/article_371.html},
eprint = {http://jas.shahroodut.ac.ir/article_371_cf285a5a87885ed211e1f128762fbc2f.pdf}
}
@article {
author = {Ahanjideh, N. and Mousavi, H.},
title = {ON THE GROUPS WITH THE PARTICULAR NON-COMMUTING GRAPHS},
journal = {Journal of Algebraic Systems},
volume = {2},
number = {2},
pages = {147-151},
year = {2015},
publisher = {Shahrood University of Technology},
issn = {2345-5128},
eissn = {2345-511X},
doi = {10.22044/jas.2015.372},
abstract = {Let $G$ be a non-abelian finite group. In this paper, we prove that $Gamma(G)$ is $K_4$-free if and only if $G cong A times P$, where $A$ is an abelian group, $P$ is a $2$-group and $G/Z(G) cong mathbb{ Z}_2 times mathbb{Z}_2$. Also, we show that $Gamma(G)$ is $K_{1,3}$-free if and only if $G cong {mathbb{S}}_3,~D_8$ or $Q_8$.},
keywords = {non-commuting graph,$K_4$-free graph,$K_{1,3}$-free graph},
url = {http://jas.shahroodut.ac.ir/article_372.html},
eprint = {http://jas.shahroodut.ac.ir/article_372_7f1845805d519f0e1594759c85b7ed9d.pdf}
}