eng
Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
2019-01-01
6
2
81
89
10.22044/jas.2018.6636.1328
1359
ON THE SPECTRUM OF DERANGEMENT GRAPHS OF ORDER A PRODUCT OF THREE PRIMES
Modjtaba Ghorbani
mghorbani@sru.ac.ir
1
Mina Rajabi-Parsa
mina.rparsa@gmail.com
2
Department of Mathematics, Faculty of Science, Shahid Rajaee Teacher Training University, 16785–136, Tehran, Iran.
Department of Mathematics, Faculty of Science, Shahid Rajaee Teacher Training University, 16785–136, Tehran, Iran.
A permutation with no fixed points is called a derangement. The subset $mathcal{D}$ of a permutation group is derangement if all elements of $mathcal{D}$ are derangement. Let $G$ be a permutation group, a derangement<br />graph is one with vertex set $G$ and derangement set $mathcal{D}$ as connecting set. In this paper, we determine the spectrum of derangement graphs of order a product of three primes.<br /><br />
http://jas.shahroodut.ac.ir/article_1359_9e89cef5779fab48c5efd555244f3eb7.pdf
permutation groups
graph eigenvalues
Frobenius group
eng
Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
2019-01-01
6
2
91
99
10.22044/jas.2018.5493.1279
1360
On $alpha $-semi-Short Modules
Maryam Davoudian
m.davoudian@scu.ac.ir
1
Department of Mathematics, Shahid Chamran University of Ahvaz, P.O. Box: 6135713895, Ahvaz, Iran.
We introduce and study the concept of $alpha $-semi short modules. Using this concept we extend some of the basic results of $alpha $-short modules to $alpha $-semi short modules. We observe that if $M$ is an $alpha $-semi short module then the dual perfect dimension of $M$ is $alpha $ or $alpha +1$. %In particular, if a semiprime ring $R$ is $alpha $-semi short as an $R$-module, then its Noetherian dimension either is $alpha$ or $alpha +1$.<br /><br />
http://jas.shahroodut.ac.ir/article_1360_7f4f6f35eeb2298932fcc91ec18e8d44.pdf
α-short modules
α-almost Noetherian modules
α-semi short modules
α-semi Noetherian modules
dual perfect dimension
eng
Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
2019-01-01
6
2
101
116
10.22044/jas.2018.6130.1305
1361
ON SEMI MAXIMAL FILTERS IN BL-ALGEBRAS
Akbar Paad
a.paad@ub.ac.ir
1
R. A. Borzooei
borzooei@sbu.ac.ir
2
Department of Mathematics, University of Bojnord, P.O.Box 9453155111, Bojnord, Iran.
Department of Mathematics, Shahid Beheshti University, P.O.Box 1983969411, Tehran, Iran
In this paper, first we study the semi maximal filters in linear $BL$-algebras and we prove that any semi maximal filter is a primary filter. Then, we investigate the radical of semi maximal filters in $BL$-algebras. Moreover, we determine the relationship between this filters and other types of filters in $BL$-algebras and G"{o} del algebra. Specially, we prove that in a G"{o}del algebra, any fantastic filter is a semi maximal filter and any semi maximal filter is an (n-fold) positive implicative filter. Also, in a $BL$-algebra, any semi maximal and implicative filter is a positive implicative filter.<br />Finally, we give an answer to the open problem in [S. Motamed, L. Torkzadeh, A. Borumand Saeid and N. Mohtashamnia, Radical of filters in BL-algebras, Math. Log. Quart. 57, No. 2, (2011), 166-179 ].
http://jas.shahroodut.ac.ir/article_1361_c9fe9e81d975c704b5be7559a1e0c091.pdf
(Semi simple)BL-algebra
G ̈odel algebra
semi maximal filter
radical of filter
eng
Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
2019-01-01
6
2
117
130
10.22044/jas.2018.5951.1298
1362
ON STRONGLY ASSOCIATIVE HYPERRINGS
Fatemeh Arabpur
f.arabpour@yahoo.com
1
Morteza Jafarpour
rmo4909@yahoo.com
2
Department of Mathematics, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.
Department of Mathematics, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.
This paper generalizes the idea of strongly associative hyperoperation introduced in [7] to the class of hyperrings. We introduce and investigate hyperrings of type 1, type 2 and SDIS. Moreover, we study some examples of these hyperrings and give a new kind of hyperrings called totally hyperrings. Totally hyperrings give us a characterization of Krasner hyperrings. Also, we investigate these strongly hyperoperations in hyperring of series.
http://jas.shahroodut.ac.ir/article_1362_b14cfdd7b20dd1bac81140e24c087680.pdf
Strongly associative hyperoperation
SDIS hyperring
Krasner hyperring
totally hyperring
hyperring of series
eng
Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
2019-01-01
6
2
131
146
10.22044/jas.2018.6312.1313
1363
ON THE CAPACITY OF EILENBERG-MACLANE AND MOORE SPACES
Mojtaba Mohareri
m.mohareri@mail.um.ac.ir
1
Behrooz Mashayekhi
bmashf@um.ac.ir
2
Hanieh Mirebrahimi
h_mirebrahimi@um.ac.ir
3
Department of Pure Mathematics, Center of Excellence in Analysis on Algebraic Structures, Ferdowsi University of Mashhad, P.O. Box: 1159-91775, Mashhad, Iran.
Department of Pure Mathematics, Center of Excellence in Analysis on Algebraic Structures, Ferdowsi University of Mashhad, P.O. Box: 1159-91775, Mashhad, Iran.
Department of Pure Mathematics, Center of Excellence in Analysis on Algebraic Structures, Ferdowsi University of Mashhad, P.O. Box: 1159-91775, Mashhad, Iran.
K. Borsuk in 1979, at the Topological Conference in Moscow, introduced concept of the capacity of a compactum and asked some questions concerning properties of the capacity of<br />compacta. In this paper, we give partial positive answers to three of these questions in some cases. In fact, by describing spaces homotopy dominated by Moore and Eilenberg-MacLane spaces, the capacities of a Moore space $M(A,n)$ and an Eilenberg-MacLane space $K(G,n)$ could be obtained. Also, we compute the capacity of wedge sum of finitely many Moore spaces of different degrees and the capacity of product of finitely many Eilenberg-MacLane spaces of different homotopy types. In particular, we compute the capacity of wedge sum of finitely many spheres of the same or different dimensions.<br /><br />
http://jas.shahroodut.ac.ir/article_1363_3d67b550b07ed03fc140c47289cd076b.pdf
Homotopy domination
Homotopy type
Eilenberg--MacLane space
Moore space
CW-complex
eng
Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
2019-01-01
6
2
147
155
10.22044/jas.2018.6849.1335
1364
ON EQUALITY OF ABSOLUTE CENTRAL AND CLASS PRESERVING AUTOMORPHISMS OF FINITE p-GROUPS
Rasoul Soleimani
rsoleimanii@yahoo.com
1
Department of Mathematics, Payame Noor University (PNU), P.O.Box 19395-3697, Tehran, Iran.
Let $G$ be a finite non-abelian $p$-group and $L(G)$ denotes the absolute center of $G$. Also, let $Aut^{L}(G)$ and $Aut_c(G)$ denote the group of all absolute central and the class preserving automorphisms of $G$, respectively. In this paper, we give a necessary and sufficient condition for $G$ such that $Aut_c(G)=Aut^{L}(G)$. We also characterize all finite non-abelian $p$-groups of order $p^n (nleq 5)$, for which every absolute central automorphism is class preserving.<br /><br />
http://jas.shahroodut.ac.ir/article_1364_aff3c1c2ba782919ee62a881ce5926c0.pdf
Automorphism group
Absolute centre
Finite p-group
eng
Shahrood University of Technology
Journal of Algebraic Systems
2345-5128
2345-511X
2019-01-01
6
2
157
167
10.22044/jas.2018.5984.1299
1365
ON GRADED INJECTIVE DIMENSION
Akram Mahmoodi
akmahmoodi@yahoo.com
1
Afsaneh Esmaeelnezhad
esmaeelnezhad81@gmail.com
2
Department of Mathematics, Payame Noor University (PNU), P.O. Box 19395- 4697, Tehran, Iran.
Department of Mathematics, Payame Noor University (PNU), P.O. Box 19395- 4697, Tehran, Iran.
There are remarkable relations between the graded homological dimensions and the ordinary homological dimensions. In this paper, we study the injective dimension of a complex of graded modules and derive its some properties. In particular, we define the $^*$dualizing complex for a graded ring and investigate its consequences.
http://jas.shahroodut.ac.ir/article_1365_4e087ce69ac02696c5bfd84864faa899.pdf
Graded rings
graded modules
injective dimension