@Article{Ozdemir2013,
author="Ozdemir, H.
and Petik, T.",
title="On the spectra of some matrices derived from two quadratic matrices",
journal="Bulletin of the Iranian Mathematical Society",
year="2013",
volume="39",
number="2",
pages="225-238",
abstract="begin{abstract} The relations between the spectrum of the matrix $Q+R$ and the spectra of the matrices $(gamma + delta)Q+(alpha + beta)R-QR-RQ$, $QR-RQ$, $alpha beta R-QRQ$, $alpha RQR-(QR)^{2}$, and $beta R-QR$ have been given on condition that the matrix $Q+R$ is diagonalizable, where $Q$, $R$ are ${alpha, beta}$-quadratic matrix and ${gamma, delta}$-quadratic matrix, respectively, of order $n$. end{abstract}",
issn="1017-060X",
doi="",
url="http://bims.iranjournals.ir/article_337.html"
}
@Article{Wang2013,
author="Wang, Q.
and Yu, G.",
title="The least-square bisymmetric solution to a quaternion matrix equation with applications",
journal="Bulletin of the Iranian Mathematical Society",
year="2013",
volume="39",
number="2",
pages="239-257",
abstract="In this paper, we derive the necessary and sufficient conditions for the quaternion matrix equation XA=B to have the least-square bisymmetric solution and give the expression of such solution when the solvability conditions are met. Futhermore, we consider the maximal and minimal inertias of the least-square bisymmetric solution to this equation. As applications, we derive sufficient and necessary conditions for XA=B to have the positive (nonnegative) definite least-square bisymmetric solution and the maximal (minimal) least-square bisymmetric solution.",
issn="1017-060X",
doi="",
url="http://bims.iranjournals.ir/article_340.html"
}
@Article{Chu2013,
author="Chu, Y.
and Hou, S.
and Xia, W.",
title="Optimal convex combinations bounds of centrodial and harmonic means for logarithmic and identric means",
journal="Bulletin of the Iranian Mathematical Society",
year="2013",
volume="39",
number="2",
pages="259-269",
abstract="We find the greatest values $alpha_{1} $ and $alpha_{2} $, and the least values $beta_{1} $ and $beta_{2} $ such that the inequalities $alpha_{1} C(a,b)+(1-alpha_{1} )H(a,b)0$ with $aneq b$. Here, $C(a,b)$, $H(a,b)$, $L(a,b)$, and $I(a,b)$ are the centroidal, harmonic, logarithmic, and identric means of two positive numbers $a$ and $b$, respectively.",
issn="1017-060X",
doi="",
url="http://bims.iranjournals.ir/article_411.html"
}
@Article{Barzegar2013,
author="Barzegar, R.
and Erfanian, A.
and Farrokhi D. G., M.",
title="Finite groups with three relative commutativity degrees",
journal="Bulletin of the Iranian Mathematical Society",
year="2013",
volume="39",
number="2",
pages="271-280",
abstract="For a finite group $G$ and a subgroup $H$ of $G$, the relative commutativity degree of $H$ in $G$, denoted by $d(H,G)$, is the probability that an element of $H$ commutes with an element of $G$. Let $mathcal{D}(G)={d(H,G):Hleq G}$ be the set of all relative commutativity degrees of subgroups of $G$. It is shown that a finite group $G$ admits three relative commutativity degrees if and only if $G/Z(G)$ is a non-cyclic group of order $pq$, where $p$ and $q$ are primes. Moreover, we determine all the relative commutativity degrees of some known groups.",
issn="1017-060X",
doi="",
url="http://bims.iranjournals.ir/article_412.html"
}
@Article{Xu2013,
author="Xu, A.
and Yan, X.",
title="Gorenstein flat and Gorenstein injective dimensions of simple modules",
journal="Bulletin of the Iranian Mathematical Society",
year="2013",
volume="39",
number="2",
pages="281-287",
abstract="Let R be a right GF-closed ring with finite left and right Gorenstein global dimension. We prove that if I is an ideal of R such that R/I is a semi-simple ring, then the Gorensntein flat dimensnion of R/I as a right R-module and the Gorensntein injective dimensnnion of R/I as a left R-module are identical. In particular, we show that for a simple module S over a commutative Gorensntein ring R, the Gorenstein flat dimension of S equals to the Gorenstein injective dimension of S.",
issn="1017-060X",
doi="",
url="http://bims.iranjournals.ir/article_413.html"
}
@Article{SalehiAmiri2013,
author="Salehi Amiri, S. S.
and Khalili Asboei, A. R.
and Iranmanesh, A.
and Tehranian, A.",
title="Quasirecognition by the prime graph of L_3(q) where 3 < q < 100",
journal="Bulletin of the Iranian Mathematical Society",
year="2013",
volume="39",
number="2",
pages="289-305",
abstract="Let $G$ be a finite group. We construct the prime graph of $ G $,which is denoted by $ Gamma(G) $ as follows: the vertex set of thisgraph is the prime divisors of $ |G| $ and two distinct vertices $ p$ and $ q $ are joined by an edge if and only if $ G $ contains anelement of order $ pq $.In this paper, we determine finite groups $ G $ with $ Gamma(G) =Gamma(L_3(q)) $, $2 leq q < 100 $ and prove that if $ q neq 2, 3$, then $L_3(q) $ is quasirecognizable by prime graph, i.e., if $G$is a finite group with the same prime graph as the finite simplegroup $L_3(q)$, then $G$ has a unique non-Abelian composition factorisomorphic to $L_3(q)$. As a consequence of our results we provethat the simple group $L_{3}(4)$ is recognizable and the simplegroups $L_{3}(7)$ and $L_{3}(9)$ are $2-$recognizable by the primegraph.",
issn="1017-060X",
doi="",
url="http://bims.iranjournals.ir/article_414.html"
}
@Article{Torres2013,
author="Torres, F. J.",
title="Existence of positive solutions for a boundary value problem of a nonlinear fractional differential equation",
journal="Bulletin of the Iranian Mathematical Society",
year="2013",
volume="39",
number="2",
pages="307-323",
abstract="This paper presents conditions for the existence and multiplicity of positive solutions for a boundary value problem of a nonlinear fractional differential equation. We show that it has at least one or two positive solutions. The main tool is Krasnosel'skii fixed point theorem on cone and fixed point index theory.",
issn="1017-060X",
doi="",
url="http://bims.iranjournals.ir/article_415.html"
}
@Article{Talebi2013,
author="Talebi, Y.
and Tribak, R.
and Moniri Hamzekolaei, A. R.",
title="On H-cofinitely supplemented modules",
journal="Bulletin of the Iranian Mathematical Society",
year="2013",
volume="39",
number="2",
pages="325-346",
abstract="A module $M$ is called $emph{H}$-cofinitely supplemented if for every cofinite submodule $E$ (i.e. $M/E$ is finitely generated) of $M$ there exists a direct summand $D$ of $M$ such that $M = E + X$ holds if and only if $M = D + X$, for every submodule $X$ of $M$. In this paper we study factors, direct summands and direct sums of $emph{H}$-cofinitely supplemented modules. Let $M$ be an $emph{H}$-cofinitely supplemented module and let $N leq M$ be a submodule. Suppose that for every direct summand $K$ of $M$, $(N + K)/N$ lies above a direct summand of $M/N$. Then $M/N$ is $emph{H}$-cofinitely supplemented. Let $M$ be an $emph{H}$-cofinitely supplemented module. Let $N$ be a direct summand of $M$. Suppose that for every direct summand $K$ of $M$ with $M=N+K$, $Ncap K$ is also a direct summand of $M$. Then $N$ is $emph{H}$-cofinitely supplemented. Let $M = M_{1} oplus M_{2}$. If $M_{1}$ is radical $M_{2}$-projective (or $M_{2}$ is radical $M_{1}$-projective) and $M_{1}$ and $M_{2}$ are $emph{H}$-cofinitely supplemented, then $M$ is $emph{H}$-cofinitely supplemented",
issn="1017-060X",
doi="",
url="http://bims.iranjournals.ir/article_416.html"
}
@Article{GhaffaryGhaleh2013,
author="Ghaffary Ghaleh, Sh.
and Ghasemi, Kh.",
title="Hyers-Ulam-Rassias stability of n-Jordan *-homomorphisms on C*-algebras",
journal="Bulletin of the Iranian Mathematical Society",
year="2013",
volume="39",
number="2",
pages="347-353",
abstract="In this paper, we introduce n-jordan homomorphisms and n-jordan *-homomorphisms and Also investigate the Hyers-Ulam-Rassiasstability of n-jordan *-homomorphisms on C*-algebras.",
issn="1017-060X",
doi="",
url="http://bims.iranjournals.ir/article_417.html"
}
@Article{Lunqun2013,
author="Lunqun, O.
and Jingwang, L.
and Yueming, X.",
title="Ore extensions of skew $pi$-Armendariz rings",
journal="Bulletin of the Iranian Mathematical Society",
year="2013",
volume="39",
number="2",
pages="355-368",
abstract="For a ring endomorphism $alpha$ and an $alpha$-derivation $delta$, we introduce a concept, so called skew $pi$-Armendariz ring, that is a generalization of both $pi$-Armendariz rings, and $(alpha,delta)$-compatible skew Armendariz rings. We first observe the basic properties of skew $pi$-Armendariz rings, and extend the class of skew $pi$-Armendariz rings through various ring extensions. We next show that all $(alpha,delta)$-compatible $NI$ rings are skew $pi$-Armendariz, and if a ring $R$ is an $(alpha,delta)$-compatible $2$-$primal$ ring, then the polynomial ring $R[x]$ is skew $pi$-Armendariz.",
issn="1017-060X",
doi="",
url="http://bims.iranjournals.ir/article_315.html"
}
@Article{Chi2013,
author="Chi, K. P.
and Karapinar, E.
and Thanh, T. D.",
title="On the fixed point theorems in generalized weakly contractive mappings on partial metric spaces",
journal="Bulletin of the Iranian Mathematical Society",
year="2013",
volume="39",
number="2",
pages="369-381",
abstract="In this paper, we prove a fixed point theorem for a pair of generalized weakly contractive mappings in complete partial metric spaces. The theorems presented are generalizations of very recent fixed point theorems due to Abdeljawad, Karapinar and Tas. To emphasize the very general nature of these results, we illustrate an example.",
issn="1017-060X",
doi="",
url="http://bims.iranjournals.ir/article_344.html"
}