Bulletin of the Iranian Mathematical Society
text
article
2017
eng
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
http://bims.iranjournals.ir/article_1182_5ac9306f6f518d1cfe3b1d5c6017a997.pdf
Benson's algorithm for nonconvex multiobjective problems via nonsmooth Wolfe duality
N.
Shafiei
Department of Mathematics, University of Isfahan, Isfahan, Iran.
author
text
article
2017
eng
In this paper, we propose an algorithm to obtain an approximation set of the (weakly) nondominated points of nonsmooth multiobjective optimization problems with equality and inequality constraints. We use an extension of the Wolfe duality to construct the separating hyperplane in Benson's outer algorithm for multiobjective programming problems with subdifferentiable functions. We also formulate an infinitive approximation set of the (weakly) nondominated points of biobjective optimization problems. Moreover, we provide some numerical examples to illustrate the advantage of our algorithm.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
975
994
http://bims.iranjournals.ir/article_968_b6e2e95fca85f00c6ce71f96f05c8755.pdf
Critical fixed point theorems in Banach algebras under weak topology features
A.
Ben Amar
Department of Mathematics,
Sfax University, Faculty of Sciences, Sfax, LA 1171, 3000, Tunisia.
author
A.
Tlili
Department of Mathematics,
Sfax University, Faculty of Sciences, Sfax, LA 1171, 3000, Tunisia.
author
text
article
2017
eng
In this paper, we establish some new critical fixed point theorems for the sum $AB+C$ in a Banach algebra relative to the weak topology, where $\frac{I-C}{A}$ allows to be noninvertible. In addition, a special class of Banach algebras will be considered.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
995
1015
http://bims.iranjournals.ir/article_969_4886e0d3f5d96cd35afe9f7650d8511a.pdf
On annihilator ideals in skew polynomial rings
M.
Zahiri
Department of Pure Mathematics, Faculty of Mathematical Sciences,
Tarbiat Modares University, P.O. Box 14115-134, Tehran, Iran.
author
A.
Moussavi
Department of Pure Mathematics, Faculty of Mathematical Sciences,
Tarbiat Modares University, P.O. Box 14115-134, Tehran, Iran.
author
R.
Mohammadi
Department of Pure Mathematics, Faculty of Mathematical Sciences,
Tarbiat Modares University, P.O. Box 14115-134, Tehran, Iran.
author
text
article
2017
eng
This article examines annihilators in the skew polynomial ring $R[x;alpha,delta]$. A ring is strongly right $AB$ if everynon-zero right annihilator is bounded. In this paper, we introduce and investigate a particular class of McCoy rings which satisfy Property ($A$) and the conditions asked by P.P. Nielsen. We assume that $R$ is an ($alpha$,$delta$)-compatible ring, and prove that, if $R$ is nil-reversible then the skew polynomial ring $R[x;alpha,delta]$is strongly right $AB$. It is also shown that, every right duo ring with an automorphism $alpha$ is skew McCoy. Moreover, if $R$ is strongly right $AB$ and skew McCoy, then $R[x;alpha]$ and $R[x;delta]$ have right Property ($A$).
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1017
1036
http://bims.iranjournals.ir/article_977_1616b5a37d6d745579be166ecbf55aa5.pdf
The norm of pre-Schwarzian derivatives on bi-univalent functions of order $\alpha$
H.
Rahmatan
Department of Mathematics, Payame Noor University, P.O. Box 19395-3697 Tehran, Iran.
author
Sh.
Najafzadeh
Department of Mathematics, Payame Noor University, P.O. Box 19395-3697 Tehran, Iran.
author
A.
Ebadian
Department of Mathematics, Payame Noor University, P.O. Box 19395-3697 Tehran, Iran.
author
text
article
2017
eng
In the present investigation, we give the best estimates for the norm of the pre-Schwarzian derivative $ T_{f}(z)=\dfrac{f^{''}(z)}{f^{'}(z)} $ for bi-starlike functions and a new subclass of bi-univalent functions of order $ \alpha $, where $\Vert T_{f} \Vert= \sup_{|z|<1} (1-|z|^{2})|\dfrac{f^{''}(z)}{f^{'}(z)}|$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1037
1043
http://bims.iranjournals.ir/article_976_ceb99544ec2644d892bcda3f82707ac5.pdf
Order-type existence theorem for second order nonlocal problems at resonance
F.
Wang
School of Mathematics and Physics, Changzhou University, Changzhou 213164, China.
author
S.
Zhang
School of Mathematics and Physics, Changzhou University, Changzhou 213164, China.
author
text
article
2017
eng
This paper gives an abstract order-type existence theorem for second order nonlocal boundary value problems at resonance and obtain existence criteria for at least two positive solutions, where $f$ is a continuous function. Our results generalize or extend related results in the literature and give a positive answer to the question raised in the literature. An example is given to illustrate the new results.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1045
1055
http://bims.iranjournals.ir/article_982_06ecbd0ed0da60644d8ee47c4455ce32.pdf
Existence and blow-up of solution of Cauchy problem for the sixth order damped Boussinesq equation
Y.
Wang
School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu 611731, P.R. China.
author
text
article
2017
eng
In this paper, we consider the existence and uniqueness of the global solution for the sixth-order damped Boussinesq equation. Moreover, the finite-time blow-up of the solution for the equation is investigated by the concavity method.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1057
1071
http://bims.iranjournals.ir/article_986_575661a92891f4b8f65f2661f90638e1.pdf
Diagonal arguments and fixed points
A.
Karimi
Department of Mathematical Sciences,
Tarbiat Modares University,
P.O. Box 14115--134,
Tehran, Iran.
author
S.
Salehi
Research Institute for Fundamental Sciences,
University of Tabriz, P.O. Box 51666--16471,
Tabriz, Iran.
author
text
article
2017
eng
A universal schema for diagonalization was popularized by N.S. Yanofsky (2003), based on a pioneering work of F.W. Lawvere (1969), in which the existence of a (diagonolized-out and contradictory) object implies the existence of a fixed-point for a certain function. It was shown that many self-referential paradoxes and diagonally proved theorems can fit in that schema. Here, we fit more theorems in the universal
schema of diagonalization, such as Euclid's proof for the infinitude of the primes and new proofs of G.~Boolos (1997) for Cantor's theorem on the non-equinumerosity of a set with its powerset. Then, in Linear Temporal Logic, we show the non-existence of a fixed-point in this logic whose proof resembles the argument of Yablo's paradox (1985, 1993). Thus, Yablo's paradox turns for the first time into a genuine mathematico-logical theorem in the framework of Linear Temporal Logic. Again the diagonal schema of the paper is used in this proof; and it is also shown that G.~Priest's inclosure schema (1997) can fit in our universal diagonal/fixed-point schema. We also show the existence of dominating (Ackermann-like) functions (which dominate a given countable set of functions, such as primitive recursive functions) in the schema.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1073
1088
http://bims.iranjournals.ir/article_979_53591d674b4feba06d0832b6aca66445.pdf
On two classes of third order boundary value problems with finite spectrum
J.J.
Ao
School of Mathematical Sciences, Inner Mongolia University, Hohhot 010021, China
and College of Sciences, Inner Mongolia University of Technology, Hohhot 010051, China.
author
text
article
2017
eng
The spectral analysis of two classes of third order boundary value problems is investigated. For every positive integer $m$ we construct two classes of regular third order boundary value problems with at most $2m+1$ eigenvalues, counting multiplicity. These kinds of finite spectrum results are previously known only for even order boundary value problems.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1089
1099
http://bims.iranjournals.ir/article_987_66c828371116cf5ebbb08bd5f732ce45.pdf
Affinization of Segre products of partial linear spaces
K.
Petelczyc
Institute of Mathematics, University of Białystok, Ciołkowskiego 1M, 15-245 Białystok.
author
M.
Żynel
Institute of Mathematics, University of Białystok, Ciołkowskiego 1M, 15-245 Białystok.
author
text
article
2017
eng
Hyperplanes and hyperplane complements in the Segre product of partial linear spaces are investigated. The parallelism of such a complement is characterized in terms of the point-line incidence. Assumptions, under which the automorphisms of the complement are the restrictions of the automorphisms of the ambient space, are given. An affine covering for the Segre product of Veblenian gamma spaces is established. A general construction that produces non-degenerate hyperplanes in the Segre product of partial linear spaces embeddable into projective space is introduced.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1101
1126
http://bims.iranjournals.ir/article_1010_ae91b745ca8ce73d8145c9d0ba456580.pdf
A new one-step iterative process for approximating common fixed points of a countable family of quasi-nonexpansive multi-valued mappings in CAT(0) spaces
S.
Suantai
Department of Mathematics, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
author
B.
Panyanak
Department of Mathematics, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
author
W.
Phuengrattana
Department of Mathematics, Faculty of Science and Technology, Nakhon Pathom Rajabhat University, Nakhon Pathom 73000, Thailand, and
Research Center for Pure and Applied Mathematics, Research and
Development Institute, Nakhon Pathom Rajabhat University, Nakhon
Pathom 73000, Thailand.
author
text
article
2017
eng
In this paper, we propose a new one-step iterative process for a countable family of quasi-nonexpansive multi-valued mappings in a CAT(0) space. We also prove strong and $Delta$-convergence theorems of the proposed iterative process under some control conditions. Our main results extend and generalize many results in the literature.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1127
1141
http://bims.iranjournals.ir/article_1011_ad0166654aaff419b6748b7e8ebe5cc1.pdf
A new characterization of $L_2(q)$ by the largest element orders
Q.H.
Jiang
School of Mathematical Sciences, University of Jinan, 250022, Shandong, China.
author
C.G.
Shao
School of Mathematical Sciences, University of Jinan, 250022, Shandong, China.
author
W.J.
Shi
Department of Mathematics, Chongqing University of Arts and Sciences, 402106, Chongqing, China.
author
Q.L.
Zhang
School of Science, NanTong University, 226019, Jiangsu, China.
author
text
article
2017
eng
We characterize the finite simple groups $L_2(q)$ by the group orders and the largest element orders, where $q$ is a prime or $q=2^a$, with $2^a+1$ or $2^a-1$ a prime.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1143
1151
http://bims.iranjournals.ir/article_1012_732dd4983f33557e48c7c70587b76a1e.pdf
A radical extension of the category of $S$-sets
M.
Haddadi
Faculty of Mathematics, Statistics and Computer Sciences, Department of Mathematics, Semnan University, Semnan, Iran.
author
M.M.
Ebrahimi
Department of Mathematics, Shahid Beheshti University, Tehran 19839, Iran.
author
text
article
2017
eng
Let S-Set be the category of $S$-sets, sets together with the actions of a semigroup $S$ on them. And, let S-Pos be the category of $S$-posets, posets together with the actions compatible with the orders on them. In this paper we show that the category S-Pos is a radical extension of S-Set; that is there is a radical on the category S-Pos, the order desolator radical, whose torsion-free class is S-Set. To do this, first we give a precise definition of a radical on the category S-Posand construct some functors between the above mentioned categories and finally we show that S-Pos is a radical extension of S-Set.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1153
1163
http://bims.iranjournals.ir/article_1013_e39fbaec4f209d34b2b2b5b8fbbd286c.pdf
A numerical method for discrete fractional--order chemostat model derived from nonstandard numerical scheme
M.
Zeinadini
Department of Mathematics, School of Mathematical Sciences,
Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.
author
M.
Namjoo
Department of Mathematics, School of Mathematical Sciences,
Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.
author
text
article
2017
eng
In this paper, the fractional--order form of three dimensional chemostat model with variable yields is introduced. The stability analysis of this fractional system is discussed in detail. In order to study the dynamic behaviours of the mentioned fractional system, the well known nonstandard (NSFD) scheme is implemented. The proposed NSFD scheme is compared with the forward Euler and fourth order Runge--Kutta methods. Numerical results show that the NSFD approach is easy and accurate when applied to fractional--order chemostat model.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1165
1182
http://bims.iranjournals.ir/article_1014_2be3d0cd976cadfa26b020f52d794dd0.pdf
On characterizations of hyperbolic harmonic Bloch and Besov spaces
X.
Fu
Department of Mathematics, Shaoxing University, Shaoxing 312000, Zhejiang Province, P.R. China.
author
text
article
2017
eng
We define hyperbolic harmonic $\omega$-$\alpha$-Bloch space $\mathcal{B}_\omega^\alpha$ in the unit ball $\mathbb{B}$ of ${\mathbb R}^n$ and characterize it in terms of $$\frac{\omega\big((1-|x|^2)^{\beta}(1-|y|^2)^{\alpha-\beta}\big)|f(x)-f(y)|}{[x,y]^\gamma|x-y|^{1-\gamma}},$$ where $0\leq \gamma\leq 1$. Similar results are extended to little $\omega$-$\alpha$-Bloch and Besov spaces. These obtained characterizations generalize the corresponding ones which were obtained by G. Ren and U. K\"{a}hler in 2002 and 2005.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1183
1194
http://bims.iranjournals.ir/article_1015_68f6233a41b79a34a80bb13734f8caa1.pdf
On the character space of Banach vector-valued function algebras
M.
Abtahi
School of Mathematics and Computer Sciences,
Damghan University, Damghan, P.O. Box 36715-364, Damghan, Iran.
author
text
article
2017
eng
Given a compact space $X$ and a commutative Banach algebra $A$, the character spaces of $A$-valued function algebras on $X$ are investigated. The class of natural $A$-valued function algebras, those whose characters can be described by means of characters of $A$ and point evaluation homomorphisms, is introduced and studied. For an admissible Banach $A$-valued function algebra $\mathscr{A}$ on $X$, conditions under which the character space $\mathfrak{M}(\mathscr{A})$ is homeomorphic to $\mathfrak{M}(\mathfrak{A})\times \mathfrak{M}(A)$ are presented, where $\mathfrak{A}=C(X) \cap\mathscr{A}$ is the subalgebra of $\mathscr{A}$ consisting of scalar-valued functions. An illustration of the results is given by some examples.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1195
1207
http://bims.iranjournals.ir/article_1016_ddcd6ea7621867940cd31a351db4ee09.pdf
On some generalized recurrent manifolds
A.A.
Shaikh
Department of Mathematics, The University of Burdwan, Golapbag, Burdwan-713104, West Bengal, India.
author
I.
Roy
Department of Mathematics, The University of Burdwan, Golapbag, Burdwan-713104, West Bengal, India.
author
H.
Kundu
Department of Mathematics, The University of Burdwan, Golapbag, Burdwan-713104, West Bengal, India.
author
text
article
2017
eng
The object of the present paper is to introduce and study a type of non-flat semi-Riemannian manifolds, called, super generalized recurrent manifolds which generalizes both the notion of hyper generalized recurrent manifolds [A.A. Shaikh and A. Patra, On a generalized class of recurrent manifolds, Arch. Math. (Brno) 46 (2010) 71--78.] and weakly generalized recurrent manifolds [A.A. Shaikh and I. Roy, On weakly generalized recurrent manifolds, Ann. Univ. Sci. Budapest Rolando Eotvos, Sect. Math. 54 (2011) 35--45.]. The nature of associated 1-forms of a super generalized recurrent manifold is determined and it is proved that on a Roter type manifold [R. Deszcz, On Roter type manifolds, in: 5th Conference on Geometry and Topology of Manifolds, Krynica, Poland, 2003.] such a notion is equivalent to the notion of generalized Ricci-recurrent manifold [U.C. De, N. Guha and D. Kamilya, On generalized Ricci-recurrent manifolds, Tensor (N.S.) 56 (1995), no. 3, 312--317.]. We also obtain a sufficient condition for a super generalized recurrent manifold to be a semisymmetric one and the existence of such notion is ensured by a proper example.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1209
1225
http://bims.iranjournals.ir/article_1017_221e80b605233294053c42a27b7694a7.pdf
A study on dimensions of modules
E.
Momtahan
Department of Mathematics, Yasouj University, Yasouj, Iran.
author
M.
Motamedi
Isfahan Mathematics House, Isfahan, Iran.
author
text
article
2017
eng
In this article we study relations between some algebraic operations such as tensor product and localization from one hand and some well-known dimensions such as uniform dimension, hollow dimension and type dimension from the other hand. Some minor applications to the ring $C(X)$ are observed.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1227
1235
http://bims.iranjournals.ir/article_1019_5f3eeaeee7edcd5ce4f9941b12e161be.pdf
On pm$^+$ and finite character bi-amalgamation
M.
Tamekkante
Department of Mathematics, Faculty
of Science, Box 11201 Zitoune, University Moulay Ismail Meknes, Morocco.
author
E.M.
Bouba
Department of Mathematics, Faculty
of Science, Box 11201 Zitoune, University Moulay Ismail Meknes, Morocco.
author
text
article
2017
eng
Let $f:A\rightarrow B$ and $g:A \rightarrow C$ be two ring homomorphisms and let $J$ and $J^{'}$ be two ideals of $B$ and $C$, respectively, such that $f^{-1}(J)=g^{-1}(J^{'})$. The bi-amalgamation of $A$ with $(B,C)$ along $(J,J^{'})$ with respect of $(f,g)$ is the subring of $B\times C$ given by $A\bowtie^{f,g}(J,J^{'})=\{(f(a)+j,g(a)+j^{'})/ a \in A, (j,j^{'}) \in J\times J^{'}\}.$ In this paper, we study the transference of $pm^{+}$, $pm$ and finite character ring-properties in the bi-amalgamation.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1237
1244
http://bims.iranjournals.ir/article_1018_d12be38a73db01fc326f798b6d1826c2.pdf
Efficient quadrature rules for a class of cordial Volterra integral equations: A comparative study
H.
Majidian
Department of Basic Sciences, Iranian Institute for Encyclopedia Research, P.O. Box 14655-478, Tehran, Iran.
author
text
article
2017
eng
A natural algorithm with an optimal order of convergence is proposed for numerical solution of a class of cordial weakly singular Volterra integral equations. The equations of this class appear in heat conduction problems with mixed boundary conditions. The algorithm is based on a representation of the solution and compound Gaussian quadrature rules with graded meshes. A comparative study is carried out, which points out that the proposed method is the most efficient one among other existing methods. In fact, the results of this paper introduce a most-efficient decisive-choice for computing the solution of the heat conduction model.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1245
1258
http://bims.iranjournals.ir/article_1020_80bdca2e204bb2940daa2f96c43eead0.pdf
On certain maximality principles
R.
Mohammadpour
Department of Mathematics and Computer Sciences, Amirkabir University of Technology,
Hafez Avenue 15194, Tehran, Iran.
author
text
article
2017
eng
We present streamlined proofs of certain maximality principles studied by Hamkins and Woodin. Moreover, we formulate an intermediate maximality principle, which is shown here to be equiconsistent with the existence of a weakly compact cardinal $\kappa$ such that $V_{\kappa}\prec V$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1259
1264
http://bims.iranjournals.ir/article_1021_ccb01899ce6ea9b8d4051086de55709f.pdf
Application of frames in Chebyshev and conjugate gradient methods
H.
Jamali
Department of mathematics, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.
author
E.
Afroomand
Department of mathematics, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.
author
text
article
2017
eng
Given a frame of a separable Hilbert space $H$, we present some iterative methods for solving an operator equation $Lu=f$, where $L$ is a bounded, invertible and symmetric operator on $H$. We present some algorithms based on the knowledge of frame bounds, Chebyshev method and conjugate gradient method, in order to give some approximated solutions to the problem. Then we investigate the convergence and optimality of them.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1265
1279
http://bims.iranjournals.ir/article_1023_0cb1da24283448175d3dd2f38ccde208.pdf
Further inequalities for operator space numerical radius on 2*2 operator matrices
M.
Sattari
Faculty of Basic Sciences, Department of Mathematics, University of Zabol, Zabol, Iran.
author
text
article
2017
eng
We present some inequalities for operator space numerical radius of $2\times 2$ block matrices on the matrix space $\mathcal{M}_n(X)$, when $X$ is a numerical radius operator space. These inequalities contain some upper and lower bounds for operator space numerical radius.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1281
1285
http://bims.iranjournals.ir/article_1022_38e5e771e877dc0dd08cba8c789de388.pdf
Stochastic evolution equations with multiplicative Poisson noise and monotone nonlinearity
E.
Salavati
School of Mathematics,
Institute for Research in Fundamental Sciences (IPM),
P.O. Box 19395-5746, Tehran, Iran
Faculty of Mathematics and Computer Science,
Amirkabir University of Technology, Tehran, Iran.
author
B.Z.
Zangeneh
Department of Mathematics, Sharif University of Technology, Tehran, Iran.
author
text
article
2017
eng
Semilinear stochastic evolution equations with multiplicative Poisson noise and monotone nonlinear drift in Hilbert spaces are considered. The coefficients are assumed to have linear growth. We do not impose coercivity conditions on coefficients. A novel method of proof for establishing existence and uniqueness of the mild solution is proposed. Examples on stochastic partial differential equations and stochastic delay differential equations are provided to demonstrate the theory developed.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1287
1299
http://bims.iranjournals.ir/article_1024_cca52c80d3906210deab1b1cc3480592.pdf
Improvements of Young inequality using the Kantorovich constant
M.
Khosravi
Department of Pure Mathematics, Faculty of Mathematics and Computer, Shahid Bahonar University of Kerman,
Kerman, Iran.
author
A.
Sheikh Hosseini
Department of Pure Mathematics, Faculty of Mathematics and Computer, Shahid Bahonar University of Kerman,
Kerman, Iran.
author
text
article
2017
eng
Some improvements of Young inequality and its reverse for positive numbers with Kantorovich constant $K(t, 2)=\frac{(1+t)^2}{4t}$ are given. Using these inequalities some operator inequalities and Hilbert-Schmidt norm versions for matrices are proved. In particular, it is shown that if $a, b$ are positive numbers and $0 \leqslant \nu \leqslant 1,$ then for all integers $ k\geqslant 1: $ $K(h^{\frac{1}{2^n}},2)^{r_n} a\sharp_{\nu}b \leqslant a\nabla_{\nu} b - \sum_{k=0}^{n-1}r_{k}\left((a \sharp_{\frac{m_k}{2^k}} b )^{\frac{1}{2}}- (a \sharp_{\frac{m_k+1}{2^k}}b )^{\frac{1}{2}}\right)^{2}\leqslant K(h^{\frac{1}{2^n}},2)^{R_n} a\sharp_{\nu}b,$ where $m_k= [ 2^k\nu ] $ is the largest integer not greater than $2^k\nu$, $ r_0=\min \{ \nu, 1-\nu\}, $ $ _{k}=\min \{ 2r_{k-1}, 1-2r_{k-1} \} $ and $R_k=1-r_k$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1301
1311
http://bims.iranjournals.ir/article_1025_461e366823aee2c9e7465c996b81443d.pdf
Dilations for $C^ast$-dynamical systems with abelian groups on Hilbert $C^ast$-modules
Z.
Wang
College of Mathematics and Information Science, Shaanxi Normal University,
Xi'an, Shaanxi, 710062, P.R. China.
author
J.
Zhang
College of Mathematics and Information Science, Shaanxi Normal University,
Xi'an, Shaanxi, 710062, P.R. China.
author
text
article
2017
eng
In this paper we investigate the dilations of completely positive definite representations of \(C^\ast\)-dynamical systems with abelian groups on Hilbert \(C^\ast\)-modules. We show that if \((\mathcal{A}, G,\alpha)\) is a \(C^\ast\)-dynamical system with \(G\) an abelian group, then every completely positive definite covariant representation \((\pi,\varphi,E)\) of \((\mathcal{A}, G,\alpha)\) on a Hilbert \(C^\ast\)-module \(E\) admits an unitary dilation $((\hat{\pi},\hat{\varphi},\hat{E})).$
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1313
1321
http://bims.iranjournals.ir/article_1026_7331f04fa6ff4e9f75048878a153860b.pdf
Some topologies on the space of quasi-multipliers
M.
Adib
Department of Mathematics, Payamenoor university(PNU), Tehran, Iran.
author
text
article
2017
eng
Assume that $A$ is a Banach algebra. We define the $\beta-$topology and the $\gamma-$topology on the space $QM_{el}(A^{*})$ of all bounded extended left quasi-multipliers of $A^{*}.$ We establish further properties of $(QM_{el}(A^{*}),\gamma)$ when $A$ is a $C^{*}-$algebra. In particular, we characterize the $\gamma-$dual of $QM_{el}(A^{*})$ and prove that $(QM_{el}(A^{*}),\gamma)^{*},$ under the topology of bounded convergence, is isomorphic to $A^{***}.$
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1323
1332
http://bims.iranjournals.ir/article_1027_45df925b9641b847aae53438ef84a853.pdf
Strongly nil-clean corner rings
P.
Danchev
Department of Mathematics, University of Plovdiv, Plovdiv 4000, Bulgaria.
author
text
article
2017
eng
We show that if $R$ is a ring with an arbitrary idempotent $e$ such that $eRe$ and $(1-e)R(1-e)$ are both strongly nil-clean rings, then $R/J(R)$ is nil-clean. In particular, under certain additional circumstances, $R$ is also nil-clean. These results somewhat improves on achievements due to Diesl in J. Algebra (2013) and to Ko\c{s}an-Wang-Zhou in J. Pure Appl. Algebra (2016). In addition, we also give a new transparent proof of the main result of Breaz-Calugareanu-Danchev-Micu in Linear Algebra Appl. (2013) which says that if $R$ is a commutative nil-clean ring, then the full $n\times n$ matrix ring $\mathbb{M}_n(R)$ is nil-clean.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1333
1339
http://bims.iranjournals.ir/article_1028_dd5007f3d112d2a8f52ea8300cd6810b.pdf
Inverse Sturm--Liouville problems using three spectra with finite number of transmissions and parameter dependent conditions
M.
Shahriari
Department of Mathematics, Faculty of Science, University of Maragheh, P.O. Box 55181-83111, Maragheh, Iran.
author
text
article
2017
eng
In this manuscript, we study various by uniqueness results for inverse spectral problems of Sturm--Liouville operators using three spectrum with a finite number of discontinuities at interior points which we impose the usual transmission conditions. We consider both the cases of classical Robin and eigenparameter dependent boundary conditions.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1341
1355
http://bims.iranjournals.ir/article_1029_93aa5b089d89ac3bbdaa647733a67c7e.pdf
Convergence of the sinc method applied to delay Volterra integral equations
L.
Shiri
Department of Mathematics, University of Mohagheghe Ardabili, 56199-11367, Ardabil, Iran.
author
M.
Zarebnia
Department of Mathematics, University of Mohagheghe Ardabili, 56199-11367, Ardabil, Iran.
author
text
article
2017
eng
In this paper, the numerical solutions of linear and nonlinear Volterra integral equations with nonvanishing delay are considered by two methods. The methods are developed by means of the sinc approximation with the single exponential (SE) and double exponential (DE) transformations. The existence and uniqueness of sinc-collocation solutions for these equations are provided. These methods improve conventional results and achieve exponential convergence. Numerical results are included to confirm the efficiency and accuracy of the methods.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1357
1375
http://bims.iranjournals.ir/article_1030_327268c4a1a76cc464033904300485c4.pdf
A stochastic version analysis of an M/G/1 retrial queue with Bernoulli schedule
M.
Boualem
Research Unit LaMOS (Modeling and Optimization of Systems), Faculty of Technology,
University of Bejaia, 06000 Bejaia, Algeria.
author
M.
Cherfaoui
Department of Mathematics, University of Biskra, Biskra 07000, Algeria
Research Unit LaMOS (Modeling and Optimization of Systems),
University of Bejaia,
06000 Bejaia, Algeria.
author
N.
Djellab
Laboratory LaPS, Department of athematics, University of Badji Mokhtar, Annaba 23000, Algeria.
author
D.
Aissani
Research Unit LaMOS (Modeling and Optimization of Systems), Faculty of Exact Sciences, University of Bejaia, 06000 Bejaia, Algeria.
author
text
article
2017
eng
In this work, we derive insensitive bounds for various performance measures of a single-server retrial queue with generally distributed inter-retrial times and Bernoulli schedule, under the special assumption that only the customer at the head of the orbit queue (i.e., a FCFS discipline governing the flow from the orbit to the server) is allowed to occupy the server. The methodology is strongly based on stochastic comparison techniques. Instead of studying a performance measure in a quantitative fashion, this approach attempts to reveal the relationship between the performance measures and the parameters of the system. We prove the monotonicity of the transition operator of the embedded Markov chain relative to strong stochastic ordering and increasing convex ordering. We obtain comparability conditions for the distribution of the number of customers in the system. Bounds are derived for the stationary distribution and some simple bounds for the mean characteristics of the system. The proofs of these results are based on the validation of some inequalities for some cumulative probabilities associated with every state $(m, n)$ of the system. Finally, the effects of various parameters on the performance of the system have been examined numerically.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1377
1397
http://bims.iranjournals.ir/article_1031_36e5f4fe5a81d41164abffb156f27b4b.pdf
An algorithm for approximating nondominated points of convex multiobjective optimization problems
M.
Ghaznavi
Faculty of Mathematics, Shahrood University of Technology, Shahrood, Iran
author
Z.
Azizi
Faculty of Mathematics, Shahrood University of Technology, Shahrood, Iran.
author
text
article
2017
eng
In this paper, we present an algorithm for generating approximate nondominated points of a multiobjective optimization problem (MOP), where the constraints and the objective functions are convex. We provide outer and inner approximations of nondominated points and prove that inner approximations provide a set of approximate weakly nondominated points. The proposed algorithm can be applied for differentiable or nondifferentiable convex MOPs. To illustrate efficiency of the proposed algorithm for convex MOPs, we provide numerical examples.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1399
1415
http://bims.iranjournals.ir/article_1032_8a34f64f24ba1df7f512341ae057ca36.pdf
Complete pivoting strategy for the $IUL$ preconditioner obtained from Backward Factored APproximate INVerse process
A.
Rafiei
Department of Applied Mathematics, Hakim Sabzevari University, Sabzevar, Iran.
author
M.
Bollhoefer
Institute computational Mathematics, Technische Universitat Braunschweig, D-38106 Braunschweig, Germany.
author
text
article
2017
eng
In this paper, we use a complete pivoting strategy to compute the IUL preconditioner obtained as the by-product of the Backward Factored APproximate INVerse process. This pivoting is based on the complete pivoting strategy of the Backward IJK version of Gaussian Elimination process. There is a parameter $\alpha$ to control the complete pivoting process. We have studied the effect of different values of $\alpha$ on the quality of the IUL preconditioner. For the numerical experiments section, the IUL factorization which is coupled with the complete pivoting is compared to the ILUTP and to the left-looking version of RIF which is coupled with the complete pivoting strategy. As the preprocessing, we have applied the maximum weighted matching coupled the Reverse Cuthill-Mckee (RCM) and multilevel nested dissection reordering.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1417
1456
http://bims.iranjournals.ir/article_1033_a0a902a62988d3118f5b4b4d8b35504d.pdf
Very cleanness of generalized matrices
Y.
Kurtulmaz
Department of Mathematics, Bilkent University, Ankara, Turkey.
author
text
article
2017
eng
An element $a$ in a ring $R$ is very clean in case there exists an idempotent $e\in R$ such that $ae = ea$ and either $a- e$ or $a + e$ is invertible. An element $a$ in a ring $R$ is very $J$-clean provided that there exists an idempotent $e\in R$ such that $ae = ea$ and either $a-e\in J(R)$ or $a + e\in J(R)$. Let $R$ be a local ring, and let $s\in C(R)$. We prove that $A\in K_s(R)$ is very clean if and only if $A\in U(K_s(R))$, $I\pm A\in U(K_s(R))$ or $A\in K_s(R)$ is very J-clean.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1457
1465
http://bims.iranjournals.ir/article_1041_38bce449953dafb7205f4ec6885c5a9c.pdf
Five-value rich lines, Borel directions and uniqueness of meromorphic functions
J.R.
Long
School of Mathematical Sciences, Guizhou Normal University, 550001, Guiyang, P.R. China
School of Computer Sciences and School of Sciences, Beijing University of Posts and Telecommunications, Beijing, 100876, P.R. China.
author
text
article
2017
eng
For a meromorphic function $f$ in the complex plane, we shall introduce the definition of five-value rich line of $f$, and study the uniqueness of meromorphic functions of finite order in an angular domain by involving the five-value rich line and Borel directions. Finally, the relationship between a five-value rich line and a Borel direction is discussed, that is, every Borel direction of $f$ is its five-value rich line, and the inverse statement holds when $f$ is of infinite order.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1467
1478
http://bims.iranjournals.ir/article_1055_2eadf39317ec9297f6148fc720caf2ce.pdf
Some rank equalities for finitely many tripotent matrices
T.
Petik
Sakarya University, Department of Mathematics, Sakarya, 54187, Turkey.
author
H.
Ozdemir
Sakarya University, Department of Mathematics, Sakarya, 54187, Turkey.
author
text
article
2017
eng
A rank equality is established for the sum of finitely many tripotent matrices via elementary block matrix operations. Moreover, by using this equality and Theorems 8 and 10 in [Chen M. and et al. On the open problem related to rank equalities for the sum of finitely many idempotent matrices and its applications, The Scientific World Journal 2014 (2014), Article ID 702413, 7 pages.], some other rank equalities for tripotent matrices are given. Furthermore, we obtain several rank equalities related to some special types of matrices, some of which are available in the literature, from the results established.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1479
1493
http://bims.iranjournals.ir/article_1037_3ff83cd867821e50f12900bc578fc89c.pdf
Convex combinations of harmonic shears of slit mappings
L.
Shi
School of Mathematics and Statistics, Anyang Normal University, Anyang 455002, Henan, P.R. China.
author
Z.-G.
Wang
School of Mathematics and Computing Science, Hunan First Normal University, Changsha 410205, Hunan, P.R. China.
author
A.
Rasila
Department of Mathematics and Systems Analysis, Aalto University, P.O. Box 11100, FI-00076 Aalto, Finland.
author
Y.
Sun
School of Science, Hunan Institute of Engineering, Xiangtan 411104, Hunan, P.R. China.
author
text
article
2017
eng
In this paper, we study the convex combinations of harmonic mappings obtained by shearing a class of slit conformal mappings. Sufficient conditions for the convex combinations of harmonic mappings of this family to be univalent and convex in the horizontal direction are derived. Several examples of univalent harmonic mappings constructed by using these methods are presented to illustrate potential applications of the main results.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1495
1510
http://bims.iranjournals.ir/article_1046_c2564c5c47e770c3777a5cef16455c1e.pdf
On a p-Laplacian system and a generalization of the Landesman-Lazer type condition
B.Q.
Hung
Faculty of Information Technology, Le Quy Don Technical University, 236 Hoang Quoc Viet, Bac Tu Liem, Hanoi, Vietnam.
author
H.Q.
Toan
Department of Mathematics, Hanoi University of Science 334 Nguyen Trai, Thanh Xuan, Ha Noi, Vietnam.
author
text
article
2017
eng
This article shows the existence of weak solutions of a resonance problem for nonuniformly p-Laplacian system in a bounded domain in $\mathbb{R}^N$. Our arguments are based on the minimum principle and rely on a generalization of the Landesman-Lazer type condition.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1511
1528
http://bims.iranjournals.ir/article_1036_a46a25c9bc4119887a0c69ea7fab5737.pdf
A simple proof of Zariski's Lemma
A.
Azarang
Department of Mathematics, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
author
text
article
2017
eng
Our aim in this very short note is to show that the proof of the following well-known fundamental lemma of Zariski follows from an argument similar to the proof of the fact that the rational field $\mathbb{Q}$ is not a finitely generated $\mathbb{Z}$-algebra.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1529
1530
http://bims.iranjournals.ir/article_1047_f803ea9ce410ca4863df36ec64d40f32.pdf
NSE characterization of some linear groups
N.
Ahanjideh
Faculty of Mathematical Sciences, Department of Pure Mathematics, Shahrekord University, Shahrekord, Iran.
author
L.
Mousavi
Department of Mathematical Sciences, Isfahan University of Technology, Isfahan 84156-83111, Iran.
author
B.
Taeri
Department of Mathematical Sciences, Isfahan University of Technology, Isfahan 84156-83111, Iran.
author
text
article
2017
eng
For a finite group $G$, let $nse(G)=\{m_k\mid k\in\pi_e(G)\}$, where $m_k$ is the number of elements of order $k$ in $G$ and $\pi_{e}(G)$ is the set of element orders of $G$. In this paper, we prove that $G\cong L_m(2)$ if and only if $p\mid |G|$ and $nse(G)=nse(L_m(2))$, where $m\in \{n,n+1\}$ and $2^n-1=p$ is a prime number.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1531
1542
http://bims.iranjournals.ir/article_1058_2c5b6c17ba5cdd918988ed6c7b89c0df.pdf
Measure of non strict singularity of Schechter essential spectrum of two bounded operators and application
F.
Abdmouleh
Institut Suprieur de Gestion Industrielle de Sfax, University
of Sfax, Route de Tunis km 10, Cite El Ons B.P 1164, 3021, Sfax, Tunisie.
author
I.
Walha
Department of Mathematics, Faculty of Sciences of Sfax, University of Sfax, Route de Soukra, Km 3.5, P.O. Box
1171, 3000, Sfax, Tunisie.
author
text
article
2017
eng
In this paper, we discuss the essential spectrum of sum of two bounded operators using measure of non strict singularity. Based on this new investigation, a problem of one-speed neutron transport operator is presented.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
5
no.
2017
1543
1558
http://bims.iranjournals.ir/article_1050_50a956cc722e6b159778d8af6ea79cff.pdf