Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Benson's algorithm for nonconvex multiobjective problems via nonsmooth Wolfe duality975994968ENN.ShafieiDepartment of Mathematics, University of Isfahan, Isfahan, Iran.Journal Article20150420In 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.http://bims.iranjournals.ir/article_968_b6e2e95fca85f00c6ce71f96f05c8755.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171001Critical fixed point theorems in Banach algebras under weak topology features9951015969ENA.Ben AmarDepartment of Mathematics,
Sfax University, Faculty of Sciences, Sfax, LA 1171, 3000, Tunisia.A.TliliDepartment of Mathematics,
Sfax University, Faculty of Sciences, Sfax, LA 1171, 3000, Tunisia.Journal Article20141028In 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.http://bims.iranjournals.ir/article_969_4886e0d3f5d96cd35afe9f7650d8511a.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171001On annihilator ideals in skew polynomial rings10171036977ENM.ZahiriDepartment of Pure Mathematics, Faculty of Mathematical Sciences,
Tarbiat Modares University, P.O. Box 14115-134, Tehran, Iran.A.MoussaviDepartment of Pure Mathematics, Faculty of Mathematical Sciences,
Tarbiat Modares University, P.O. Box 14115-134, Tehran, Iran.R.MohammadiDepartment of Pure Mathematics, Faculty of Mathematical Sciences,
Tarbiat Modares University, P.O. Box 14115-134, Tehran, Iran.Journal Article20140930This article examines annihilators in the skew polynomial ring $R[x;alpha,delta]$. A ring is strongly right $AB$ if every<br />non-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 $R[x;alpha,delta]$<br />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 ($A$).http://bims.iranjournals.ir/article_977_1616b5a37d6d745579be166ecbf55aa5.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171001The norm of pre-Schwarzian derivatives on bi-univalent functions of order $\alpha$10371043976ENH.RahmatanDepartment of Mathematics, Payame Noor University, P.O. Box 19395-3697 Tehran, Iran.Sh.NajafzadehDepartment of Mathematics, Payame Noor University, P.O. Box 19395-3697 Tehran, Iran.A.EbadianDepartment of Mathematics, Payame Noor University, P.O. Box 19395-3697 Tehran, Iran.Journal Article20150613In 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 $\Vert T_{f} \Vert= \sup_{|z|<1} (1-|z|^{2})|\dfrac{f^{''}(z)}{f^{'}(z)}|$.http://bims.iranjournals.ir/article_976_ceb99544ec2644d892bcda3f82707ac5.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Order-type existence theorem for second order nonlocal problems at resonance10451055982ENF.WangSchool of Mathematics and Physics, Changzhou University, Changzhou 213164, China.S.ZhangSchool of Mathematics and Physics, Changzhou University, Changzhou 213164, China.Journal Article20150915This 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.http://bims.iranjournals.ir/article_982_06ecbd0ed0da60644d8ee47c4455ce32.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171001Existence and blow-up of solution of Cauchy problem for the sixth order damped Boussinesq equation10571071986ENY.WangSchool of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu 611731, P.R. China.Journal Article20141102In 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.http://bims.iranjournals.ir/article_986_575661a92891f4b8f65f2661f90638e1.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171001Diagonal arguments and fixed points10731088979ENA.KarimiDepartment of Mathematical Sciences,
Tarbiat Modares University,
P.O. Box 14115--134,
Tehran, Iran.S.SalehiResearch Institute for Fundamental Sciences,
University of Tabriz, P.O. Box 51666--16471,
Tabriz, Iran.Journal Article20151101A 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.http://bims.iranjournals.ir/article_979_53591d674b4feba06d0832b6aca66445.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171001On two classes of third order boundary value problems with finite spectrum10891099987ENJ.J.AoSchool of Mathematical Sciences, Inner Mongolia University, Hohhot 010021, China
and College of Sciences, Inner Mongolia University of Technology, Hohhot 010051, China.Journal Article20151108The 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.http://bims.iranjournals.ir/article_987_66c828371116cf5ebbb08bd5f732ce45.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Affinization of Segre products of partial linear spaces110111261010ENK.PetelczycInstitute of Mathematics, University of Białystok, Ciołkowskiego 1M, 15-245 Białystok.M.ŻynelInstitute of Mathematics, University of Białystok, Ciołkowskiego 1M, 15-245 Białystok.Journal Article20160405Hyperplanes 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.<br /> 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.http://bims.iranjournals.ir/article_1010_ae91b745ca8ce73d8145c9d0ba456580.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171001A new one-step iterative process for approximating common fixed points of a countable family of quasi-nonexpansive multi-valued mappings in CAT(0) spaces112711411011ENS.SuantaiDepartment of Mathematics, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.B.PanyanakDepartment of Mathematics, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.W.PhuengrattanaDepartment 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.Journal Article20150703In 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.http://bims.iranjournals.ir/article_1011_ad0166654aaff419b6748b7e8ebe5cc1.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031A new characterization of $L_2(q)$ by the largest element orders114311511012ENQ.H.JiangSchool of Mathematical Sciences, University of Jinan, 250022, Shandong, China.C.G.ShaoSchool of Mathematical Sciences, University of Jinan, 250022, Shandong, China.W.J.ShiDepartment of Mathematics, Chongqing University of Arts and Sciences, 402106, Chongqing, China.Q.L.ZhangSchool of Science, NanTong University, 226019, Jiangsu, China.Journal Article20130825We 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.<br /> http://bims.iranjournals.ir/article_1012_732dd4983f33557e48c7c70587b76a1e.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031A radical extension of the category of $S$-sets115311631013ENM.HaddadiFaculty of Mathematics, Statistics and Computer Sciences, Department of Mathematics, Semnan University, Semnan, Iran.M.M.EbrahimiDepartment of Mathematics, Shahid Beheshti University, Tehran 19839, Iran.Journal Article20150204Let 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.<br /><br /> 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.http://bims.iranjournals.ir/article_1013_e39fbaec4f209d34b2b2b5b8fbbd286c.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031A numerical method for discrete fractional--order chemostat model derived from nonstandard numerical scheme116511821014ENM.ZeinadiniDepartment of Mathematics, School of Mathematical Sciences,
Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.M.NamjooDepartment of Mathematics, School of Mathematical Sciences,
Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.Journal Article20150906In 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.http://bims.iranjournals.ir/article_1014_2be3d0cd976cadfa26b020f52d794dd0.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031On characterizations of hyperbolic harmonic Bloch and Besov spaces118311941015ENX.FuDepartment of Mathematics, Shaoxing University, Shaoxing 312000, Zhejiang Province, P.R. China.Journal Article20151116We 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.http://bims.iranjournals.ir/article_1015_68f6233a41b79a34a80bb13734f8caa1.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031On the character space of Banach vector-valued function algebras119512071016ENM.AbtahiSchool of Mathematics and Computer Sciences,
Damghan University, Damghan, P.O. Box 36715-364, Damghan, Iran.Journal Article20160102Given 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.http://bims.iranjournals.ir/article_1016_ddcd6ea7621867940cd31a351db4ee09.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031On some generalized recurrent manifolds120912251017ENA.A.ShaikhDepartment of Mathematics, The University of Burdwan, Golapbag, Burdwan-713104, West Bengal, India.I.RoyDepartment of Mathematics, The University of Burdwan, Golapbag, Burdwan-713104, West Bengal, India.H.KunduDepartment of Mathematics, The University of Burdwan, Golapbag, Burdwan-713104, West Bengal, India.Journal Article20150326The 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.http://bims.iranjournals.ir/article_1017_221e80b605233294053c42a27b7694a7.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031A study on dimensions of modules122712351019ENE.MomtahanDepartment of Mathematics, Yasouj University, Yasouj, Iran.M.MotamediIsfahan Mathematics House, Isfahan, Iran.Journal Article20150510In 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.http://bims.iranjournals.ir/article_1019_5f3eeaeee7edcd5ce4f9941b12e161be.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031On pm$^+$ and finite character bi-amalgamation123712441018ENM.TamekkanteDepartment of Mathematics, Faculty
of Science, Box 11201 Zitoune, University Moulay Ismail Meknes, Morocco.E.M.BoubaDepartment of Mathematics, Faculty
of Science, Box 11201 Zitoune, University Moulay Ismail Meknes, Morocco.Journal Article20160313Let $f:A\rightarrow B$ 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.http://bims.iranjournals.ir/article_1018_d12be38a73db01fc326f798b6d1826c2.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171001Efficient quadrature rules for a class of cordial Volterra integral equations: A comparative study124512581020ENH.MajidianDepartment of Basic Sciences, Iranian Institute for Encyclopedia Research, P.O. Box 14655-478, Tehran, Iran.Journal Article20151219A 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. http://bims.iranjournals.ir/article_1020_80bdca2e204bb2940daa2f96c43eead0.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031On certain maximality principles125912641021ENR.MohammadpourDepartment of Mathematics and Computer Sciences, Amirkabir University of Technology,
Hafez Avenue 15194, Tehran, Iran.Journal Article20160306We 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 $V_{\kappa}\prec V$.http://bims.iranjournals.ir/article_1021_ccb01899ce6ea9b8d4051086de55709f.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Application of frames in Chebyshev and conjugate gradient methods126512791023ENH.JamaliDepartment of mathematics, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.E.AfroomandDepartment of mathematics, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.Journal Article20150831Given 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.http://bims.iranjournals.ir/article_1023_0cb1da24283448175d3dd2f38ccde208.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Further inequalities for operator space numerical radius on 2*2 operator matrices128112851022ENM.SattariFaculty of Basic Sciences, Department of Mathematics, University of Zabol, Zabol, Iran.Journal Article20160102We 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.http://bims.iranjournals.ir/article_1022_38e5e771e877dc0dd08cba8c789de388.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171001Stochastic evolution equations with multiplicative Poisson noise and monotone nonlinearity128712991024ENE.SalavatiSchool 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.B.Z.ZangenehDepartment of Mathematics, Sharif University of Technology, Tehran, Iran.Journal Article20151010Semilinear 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.http://bims.iranjournals.ir/article_1024_cca52c80d3906210deab1b1cc3480592.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Improvements of Young inequality using the Kantorovich constant130113111025ENM.KhosraviDepartment of Pure Mathematics, Faculty of Mathematics and Computer, Shahid Bahonar University of Kerman,
Kerman, Iran.A.Sheikh HosseiniDepartment of Pure Mathematics, Faculty of Mathematics and Computer, Shahid Bahonar University of Kerman,
Kerman, Iran.Journal Article20151225Some 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: $<br /> $K(h^{\frac{1}{2^n}},2)^{r_n} a\sharp_{\nu}b \leqslant a\nabla_{\nu} b - \sum_{k=0}^{n-1}r_{k}\left((a \sharp_{\frac{m_k}{2^k}} b )^{\frac{1}{2}}- (a \sharp_{\frac{m_k+1}{2^k}}b )^{\frac{1}{2}}\right)^{2}\leqslant K(h^{\frac{1}{2^n}},2)^{R_n} a\sharp_{\nu}b,$<br /> 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 $R_k=1-r_k$.http://bims.iranjournals.ir/article_1025_461e366823aee2c9e7465c996b81443d.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Dilations for $C^ast$-dynamical systems with abelian groups on Hilbert $C^ast$-modules131313211026ENZ.WangCollege of Mathematics and Information Science, Shaanxi Normal University,
Xi'an, Shaanxi, 710062, P.R. China.J.ZhangCollege of Mathematics and Information Science, Shaanxi Normal University,
Xi'an, Shaanxi, 710062, P.R. China.Journal Article20150610In 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 $((\hat{\pi},\hat{\varphi},\hat{E})).$http://bims.iranjournals.ir/article_1026_7331f04fa6ff4e9f75048878a153860b.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Some topologies on the space of quasi-multipliers132313321027ENM.AdibDepartment of Mathematics, Payamenoor university(PNU), Tehran, Iran.Journal Article20160226Assume 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 $A^{***}.$http://bims.iranjournals.ir/article_1027_45df925b9641b847aae53438ef84a853.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Strongly nil-clean corner rings133313391028ENP.DanchevDepartment of Mathematics, University of Plovdiv, Plovdiv 4000, Bulgaria.Journal Article20160319We 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.http://bims.iranjournals.ir/article_1028_dd5007f3d112d2a8f52ea8300cd6810b.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Inverse Sturm--Liouville problems using three spectra with finite number of transmissions and parameter dependent conditions134113551029ENM.ShahriariDepartment of Mathematics, Faculty of Science, University of Maragheh, P.O. Box 55181-83111, Maragheh, Iran.Journal Article20140721In 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.http://bims.iranjournals.ir/article_1029_93aa5b089d89ac3bbdaa647733a67c7e.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Convergence of the sinc method applied to delay Volterra integral equations135713751030ENL.ShiriDepartment of Mathematics, University of Mohagheghe Ardabili, 56199-11367, Ardabil, Iran.M.ZarebniaDepartment of Mathematics, University of Mohagheghe Ardabili, 56199-11367, Ardabil, Iran.Journal Article20150616In 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.http://bims.iranjournals.ir/article_1030_327268c4a1a76cc464033904300485c4.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031A stochastic version analysis of an M/G/1 retrial queue with Bernoulli schedule137713971031ENM.BoualemResearch Unit LaMOS (Modeling and Optimization of Systems), Faculty of Technology,
University of Bejaia, 06000 Bejaia, Algeria.M.CherfaouiDepartment of Mathematics, University of Biskra, Biskra 07000, Algeria
Research Unit LaMOS (Modeling and Optimization of Systems),
University of Bejaia,
06000 Bejaia, Algeria.N.DjellabLaboratory LaPS, Department of athematics, University of Badji Mokhtar, Annaba 23000, Algeria.D.AissaniResearch Unit LaMOS (Modeling and Optimization of Systems), Faculty of Exact Sciences, University of Bejaia, 06000 Bejaia, Algeria.Journal Article20151102In 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.http://bims.iranjournals.ir/article_1031_36e5f4fe5a81d41164abffb156f27b4b.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031An algorithm for approximating nondominated points of convex multiobjective optimization problems139914151032ENM.GhaznaviFaculty of Mathematics, Shahrood University of Technology, Shahrood, IranZ.AziziFaculty of Mathematics, Shahrood University of Technology, Shahrood, Iran.Journal Article20150828In 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.http://bims.iranjournals.ir/article_1032_8a34f64f24ba1df7f512341ae057ca36.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Complete pivoting strategy for the $IUL$ preconditioner obtained from Backward Factored APproximate INVerse process141714561033ENA.RafieiDepartment of Applied Mathematics, Hakim Sabzevari University, Sabzevar, Iran.M.BollhoeferInstitute computational Mathematics, Technische Universitat Braunschweig, D-38106 Braunschweig, Germany.Journal Article20160102In 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.http://bims.iranjournals.ir/article_1033_a0a902a62988d3118f5b4b4d8b35504d.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Very cleanness of generalized matrices145714651041ENY.KurtulmazDepartment of Mathematics, Bilkent University, Ankara, Turkey.Journal Article20160621An 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.http://bims.iranjournals.ir/article_1041_38bce449953dafb7205f4ec6885c5a9c.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Five-value rich lines, Borel directions and uniqueness of meromorphic functions146714781055ENJ.R.LongSchool 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.Journal Article20151031For 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.http://bims.iranjournals.ir/article_1055_2eadf39317ec9297f6148fc720caf2ce.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Some rank equalities for finitely many tripotent matrices147914931037ENT.PetikSakarya University, Department of Mathematics, Sakarya, 54187, Turkey.H.OzdemirSakarya University, Department of Mathematics, Sakarya, 54187, Turkey.Journal Article20150706A 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.http://bims.iranjournals.ir/article_1037_3ff83cd867821e50f12900bc578fc89c.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031Convex combinations of harmonic shears of slit mappings149515101046ENL.ShiSchool of Mathematics and Statistics, Anyang Normal University, Anyang 455002, Henan, P.R. China.Z.-G.WangSchool of Mathematics and Computing Science, Hunan First Normal University, Changsha 410205, Hunan, P.R. China.A.RasilaDepartment of Mathematics and Systems Analysis, Aalto University, P.O. Box 11100, FI-00076 Aalto, Finland.Y.SunSchool of Science, Hunan Institute of Engineering, Xiangtan 411104, Hunan, P.R. China.Journal Article20160227In 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.http://bims.iranjournals.ir/article_1046_c2564c5c47e770c3777a5cef16455c1e.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031On a p-Laplacian system and a generalization of the Landesman-Lazer type condition151115281036ENB.Q.HungFaculty of Information Technology, Le Quy Don Technical University, 236 Hoang Quoc Viet, Bac Tu Liem, Hanoi, Vietnam.H.Q.ToanDepartment of Mathematics, Hanoi University of Science 334 Nguyen Trai, Thanh Xuan, Ha Noi, Vietnam.Journal Article20160228This 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.http://bims.iranjournals.ir/article_1036_a46a25c9bc4119887a0c69ea7fab5737.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031A simple proof of Zariski's Lemma152915301047ENA.AzarangDepartment of Mathematics, Shahid Chamran University of Ahvaz, Ahvaz, Iran.Journal Article20160704Our 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.http://bims.iranjournals.ir/article_1047_f803ea9ce410ca4863df36ec64d40f32.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171031NSE characterization of some linear groups153115421058ENN.AhanjidehFaculty of Mathematical Sciences, Department of Pure Mathematics, Shahrekord University, Shahrekord, Iran.L.MousaviDepartment of Mathematical Sciences, Isfahan University of Technology, Isfahan 84156-83111, Iran.B.TaeriDepartment of Mathematical Sciences, Isfahan University of Technology, Isfahan 84156-83111, Iran.Journal Article20160424For 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.http://bims.iranjournals.ir/article_1058_2c5b6c17ba5cdd918988ed6c7b89c0df.pdfIranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X43520171001Measure of non strict singularity of Schechter essential spectrum of two bounded operators and application154315581050ENF.AbdmoulehInstitut Suprieur de Gestion Industrielle de Sfax, University
of Sfax, Route de Tunis km 10, Cite El Ons B.P 1164, 3021, Sfax, Tunisie.I.WalhaDepartment of Mathematics, Faculty of Sciences of Sfax, University of Sfax, Route de Soukra, Km 3.5, P.O. Box
1171, 3000, Sfax, Tunisie.Journal Article20160505In 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.http://bims.iranjournals.ir/article_1050_50a956cc722e6b159778d8af6ea79cff.pdf