2018-01-21T07:56:41Z
http://bims.iranjournals.ir/?_action=export&rf=summon&issue=65
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
Bulletin of the Iranian Mathematical Society
2014
04
01
http://bims.iranjournals.ir/article_497_9cc7d666394b4cb7b0b14500de20ed08.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
Finite iterative methods for solving systems of linear matrix equations over reflexive and anti-reflexive matrices
Mehdi
Dehghan
Masoud
Hajarian
A matrix $Pintextmd{C}^{ntimes n}$ is called a generalized reflection matrix if $P^{H}=P$ and $P^{2}=I$. An $ntimes n$ complex matrix $A$ is said to be a reflexive (anti-reflexive) matrix with respect to the generalized reflection matrix $P$ if $A=PAP$ ($A=-PAP$). In this paper, we introduce two iterative methods for solving the pair of matrix equations $AXB=C$ and $DXE=F$ over reflexive and anti-reflexive matrices. The convergence of the iterative methods is also proposed. Finally, a numerical example is given to show the efficiency of the presented results.
Matrix equation
Reflexive matrix
Anti-reflexive matrix
2014
04
01
295
323
http://bims.iranjournals.ir/article_498_e826f705a8bcdc93e8b4e86ef70af573.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
Bilateral composition operators on vector-valued Hardy spaces
Hamid
Rezaei
Let $T$ be a bounded operator on the Banach space $X$ and $ph$ be an analytic self-map of the unit disk $Bbb{D}$. We investigate some operator theoretic properties of bilateral composition operator $C_{ph, T}: f ri T circ f circ ph$ on the vector-valued Hardy space $H^p(X)$ for $1 leq p leq +infty$. Compactness and weak compactness of $C_{ph, T}$ on $H^p(X)$ are characterized and when $p=2$, a concrete formula for its adjoint is given.
vector-valued Hardy space
composition operator
linear fractional map
weak compactness
2014
04
01
325
337
http://bims.iranjournals.ir/article_499_de6518007dfc715846c6f2e18e395a31.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
Periodically correlated and multivariate symmetric stable processes related to periodic and cyclic flows
Afshin
Parvardeh
Sareh
Goliforushani
Ahmad Reza
Soltani
In this work we introduce and study discrete time periodically correlated stable processes and multivariate stationary stable processes related to periodic and cyclic flows. Our study involves producing a spectral representation and a spectral identification for such processes. We show that the third component of a periodically correlated stable process has a component related to a periodic-cyclic flow.
multivariate stationary stable processes
flows
periodic and cyclic flows
2014
04
01
339
355
http://bims.iranjournals.ir/article_500_37ead49e70ddc70e5d343101a2a9cebe.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
Improvements of two preconditioned AOR iterative methods for Z-matrices
Mohsen
Hasani
Davod
Khojasteh Salkuyeh
In this paper, we propose two preconditioned AOR iterative methods to solve systems of linear equations whose coefficient matrices are Z-matrix. These methods can be considered as improvements of two previously presented ones in the literature. Finally some numerical experiments are given to show the effectiveness of the proposed preconditioners.
System of linear equations
preconditioner
AOR iterative method
Z-matrix
2014
04
01
357
371
http://bims.iranjournals.ir/article_501_8a1c873672368b347de367b050646428.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
Ostrowski type inequalities for functions whose derivatives are preinvex
Imdat
Işcan
In this paper, making use of a new identity, we establish new inequalities of Ostrowski type for the class of preinvex functions and gave some midpoint type inequalities.
Ostrowski type inequalities
preinvex function
condition C
2014
04
01
373
386
http://bims.iranjournals.ir/article_502_aa3a54cac93833e16043e4a243cffb1f.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
On the decomposable numerical range of operators
Yousef
Zamani
Sima
Ahsani
Let $V$ be an $n$-dimensional complex inner product space. Suppose $H$ is a subgroup of the symmetric group of degree $m$, and $chi :Hrightarrow mathbb{C} $ is an irreducible character (not necessarily linear). Denote by $V_{chi}(H)$ the symmetry class of tensors associated with $H$ and $chi$. Let $K(T)in
(V_{chi}(H))$ be the operator induced by $Tin
text{End}(V)$. The decomposable numerical range $W_{chi}(T)$ of
$T$ is a subset of the classical numerical range $W(K(T))$ of $K(T)$ defined as:$$
W_{chi}(T)={(K(T)x^{ast }, x^{ast}):x^{ast } is a decomposable unit tensor}.$$
In this paper, we study the interplay between the geometric properties of $W_{chi}(T)$ and the algebraic properties of $T$. In fact, we extend some of the results of [C. K. Li and A. Zaharia, Decomposable numerical range on orthonormal decomposable tensors, Linear Algebra Appl. 308 (2000), no, 1-3, 139--152] and [C. K. Li and A. Zaharia, Induced operators on symmetry classes of tensors, Trans. Amer. Math. Soc. 354 (2002), no. 2, 807--836], to non-linear irreducible characters.
symmetry class of tensors
decomposable
numerical range
induced operator
2014
04
01
387
398
http://bims.iranjournals.ir/article_503_b7e2e3cc8e6d67d8124fdf498d842b65.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
WZ factorization via Abay-Broyden-Spedicato algorithms
Effat
Golpar-Raboky
N.
Mahdavi-Amiri
Classes of Abaffy-Broyden-Spedicato (ABS) methods have been introduced for solving linear systems of equations. The algorithms are powerful methods for developing matrix factorizations and many fundamental numerical linear algebra processes. Here, we show how to apply the ABS algorithms to devise algorithms to compute the WZ and ZW factorizations of a nonsingular matrix as well as the $W^TW$ and $Z^TZ$ factorizations of a symmetric positives definite matrix. We also describe the QZ and the QW factorizations, with Q orthogonal, and show how to appropriate the parameters of the ABS algorithms to compute these factorizations.
ABS algorithms
WZ factorization
ZW factorizatio
WTW factorization
ZTZ factorization
QZ factoriation
QW factorization
2014
04
01
399
411
http://bims.iranjournals.ir/article_504_cc2f035a33cf3308b3f1d82d42cd6624.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
A graphical difference between the inverse and regular semigroups
Ayoub
Gharibkhajeh
Hossein
Doostie
In this paper we investigate the Green graphs for the regular and inverse semigroups by considering the Green classes of them. And by using the properties of these semigroups, we prove that all of the five Green graphs for the inverse semigroups are isomorphic complete graphs, while this doesn't hold for the regular semigroups. In other words, we prove that in a regular semigroup $S$ two Green graph $Gamma_{mathcal{L}}(S)$ and $Gamma_{mathcal{H}}(S)$ are isomorphic, however, the other three Green graphs are non-isomorphic to them.
Regular and inverse semigroup
Green relations
Green graphs
2014
04
01
413
421
http://bims.iranjournals.ir/article_505_8d4a7f029daec49b029448a7f5252b20.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
Gorenstein global dimensions for Hopf algebra actions
Qunxing
Pan
Faqun
Cai
Let $H$ be a Hopf algebra and $A$ an $H$-bimodule algebra. In this paper, we investigate Gorenstein global dimensions for Hopf algebras and twisted smash product algebras $Astar H$. Results from the literature are generalized.
Hopf algebras
Gorenstein global
dimensions
Morita equivalence
twisted smash products
2014
04
01
423
431
http://bims.iranjournals.ir/article_506_9440f67571725993f34bcd0d32f3296c.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
$(m,n)$-algebraically compactness and $(m,n)$-pure injectivity
Mahmood
Behboodi
Atefeh
Ghorbani
Seyed Hossein
Shojaee
In this paper, we introduce the notion of $(m,n)$-algebraically compact modules as an analogue of algebraically compact modules and then we show that $(m,n)$-algebraically compactness and $(m,n)$-pure injectivity for modules coincide. Moreover, further characterizations of a $(m,n)$-pure injective module over a commutative ring are given.
(n
m)-pure exact
m)-pure injective
m)-algebraically compact
pure injective
algebraically compact
2014
04
01
433
445
http://bims.iranjournals.ir/article_507_09d25bec7f5a7b3bdf5caa983c9d38ba.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
A Stochastic algorithm to solve multiple dimensional Fredholm integral equations of the second kind
Rahman
Farnoosh
Mahboubeh
Aalaei
In the present work, a new stochastic algorithm is proposed to solve multiple dimensional Fredholm integral equations of the second kind. The solution of the integral equation is described by the Neumann series expansion. Each term of this expansion can be considered as an expectation which is approximated by a continuous Markov chain Monte Carlo method. An algorithm is proposed to simulate a continuous Markov chain with probability density function arisen from an importance sampling technique. Theoretical results are established in a normed space to justify the convergence of the proposed method. The method has a simple structure and it is a good candidate for parallelization because of the fact that many independent sample paths are used to estimate the solution. Numerical results are performed in order to confirm the efficiency and accuracy of the present work.
Fredholm integral equations
Monte Carlo method
Continuous Markov chain
Neumann series expansion
Importance sampling
2014
04
01
447
458
http://bims.iranjournals.ir/article_508_c94cabec98592f562c8a3e4567221f96.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
On $I$-statistical and $I$-lacunary statistical convergence of order $alpha$
Pratulananda
Das
Ekrem
Savas
In this paper, following a very recent and new approach, we further generalize recently introduced summability methods, namely, $I$-statistical convergence and $I$-lacunary statistical convergence (which extend the important summability methods, statistical convergence and lacunary statistical convergence using ideals of $mathbb{N}$) and introduce the notions of $I$-statistical convergence of order $alpha$ and $I$-lacunary statistical convergence of order $alpha$, where $0
I-statistical convergence
I-lacunary statistical convergence
statistical convergence of order $alpha$
2014
04
01
459
472
http://bims.iranjournals.ir/article_509_fe820582c3d031263737aa3b6e5a7007.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
A characterization of the symmetric group of prime degree
Qingliang
Zhang
Jinhua
Wang
Weijun
Liu
Let $G$ be a finite group and $Gamma(G)$ the prime graph of $G$. Recently people have been using prime graphs to study simple groups. Naturally we pose a question: can we use prime graphs to study almost simple groups or non-simple groups? In this paper some results in this respect are obtained and as follows: $Gcong S_p$ if and only if $|G|=|S_p|$ and $Gamma(G)=Gamma(S_p)$, where $p$ is a prime.
characterization
symmetric group
Prime graph
2014
04
01
473
480
http://bims.iranjournals.ir/article_510_dee5dd7e5a3f35385b5ddbc71bf0cc1b.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
Approximating fixed points of nonexpansive mappings and solving systems of variational inequalities
Hossein
Piri
A new approximation method for the set of common fixed points of nonexpansive mappings and the set of solutions of systems of variational inequalities is introduced and studied. Moreover, we apply our main result to obtain strong convergence theorem to a common fixed point of a nonexpannsive mapping and solutions of a system of variational inequalities of an inverse strongly monotone mapping and strictly pseudo-contractive mapping of Browder-Petryshyn type.
fixed point
$delta$- strongly monotone
$lambda$- strictly pseudo-contractive
2014
04
01
481
504
http://bims.iranjournals.ir/article_511_d0c5befcc72c8fd3470d89ccbd4d2ba3.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
Arens regularity of bilinear forms and unital Banach module spaces
kazem
Haghnejad Azar
Assume that $A$, $B$ are Banach algebras and that $m:Atimes Brightarrow B$, $m^prime:Atimes Arightarrow B$ are bounded bilinear mappings. We study the relationships between Arens regularity of $m$, $m^prime$ and the Banach algebras $A$, $B$. For a Banach $A$-bimodule $B$, we show that $B$ factors with respect to $A$ if and only if $B^{**}$ is unital as an $A^{**}$-module. Let $Z_{e^{primeprime}}(B^{**})=B^{**}$ where $e^{primeprime}$ is a mixed unit of $A^{**}$. Then $B^*$ factors on both sides with respect to $A$ if and only if $B^{**}$ has a unit as $A^{**}$-module.
Arens regularity
bilinear mappings
Topological center
Unital A-module
Module action
2014
04
01
505
520
http://bims.iranjournals.ir/article_512_7cc3f3725b7b3c1fe554083605917069.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
Weak Banach-Saks property in the space of compact operators
B. Khadijeh
Moosavi
S. Mohammad
Moshtaghioun
For suitable Banach spaces $X$ and $Y$ with Schauder decompositions and a suitable closed subspace $mathcal{M}$ of some compact operator space from $X$ to $Y$, it is shown that the strong Banach-Saks-ness of all evaluation operators on ${mathcal M}$ is a sufficient condition for the weak Banach-Saks property of ${mathcal M}$, where for each $xin X$ and $y^*in Y^*$, the evaluation operators on $mathcal{M}$ are defined by $phi_x(T)= Tx$ and $psi_{y^*}(T)= T^*y^*.$
weak Banach-Saks property
P- property
Schauder decomposition
compact operator
completely continuous operator
2014
04
01
521
530
http://bims.iranjournals.ir/article_513_d1178361f94ff0d658d4159f2e3bc59b.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2014
40
2
On generalisations of almost prime and weakly prime ideals
Mahdieh
Ebrahimpour
Let $R$ be a commutative ring with identity. A proper ideal $P$ of $R$ is a $(n-1,n)$-$Phi_m$-prime ($(n-1,n)$-weakly prime) ideal if $a_1,ldots,a_nin R$, $a_1cdots a_nin Pbackslash P^m$ ($a_1cdots a_nin Pbackslash {0}$) implies $a_1cdots a_{i-1}a_{i+1}cdots a_nin P$, for some $iin{1,ldots,n}$; ($m,ngeq 2$). In this paper several results concerning $(n-1,n)$-$Phi_m$-prime and $(n-1,n)$-weakly prime ideals are proved. We show that in a Noetherian domain a $Phi_m$-prime ideal is primary and we show that in some well known rings $(n-1,n)$-$Phi_m$-prime ideals and $(n-1,n)$-prime ideals coincide.
Quasi-local ring
prime ideal
almost prime ideal
$(n-1
n)$-weakly prime ideal
n)$-$Phi_m$-prime ideal
2014
04
01
531
540
http://bims.iranjournals.ir/article_514_6d6ae9529874c4c6f84dc631664e5962.pdf