Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 ‎Finite iterative methods for solving systems of linear matrix equations over reflexive and anti-reflexive matrices 295 323 EN Mehdi Dehghan Prof. dehghan@aut.ac.ir Masoud Hajarian Department of Mathematics Faculty of Mathematical Sciences Shahid Beheshti University, G.C., Evin, Tehran 19839 Iran mhajarian@aut.ac.ir 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 http://bims.iranjournals.ir/article_498.html http://bims.iranjournals.ir/article_498_e826f705a8bcdc93e8b4e86ef70af573.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 Bilateral composition operators on vector-valued Hardy spaces 325 337 EN Hamid Rezaei Yasouj University rezaei@mail.yu.ac.ir 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 http://bims.iranjournals.ir/article_499.html http://bims.iranjournals.ir/article_499_de6518007dfc715846c6f2e18e395a31.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 Periodically correlated and multivariate symmetric stable‎ ‎processes related to periodic and cyclic flows 339 355 EN Afshin Parvardeh Academic Professor a.parvardeh@sci.ui.ac.ir Sareh Goliforushani Academic Professor sareh.goli@gmail.com Ahmad Reza Soltani Academic Professor soltani@kuc01.kuniv.edu.kw ‎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 http://bims.iranjournals.ir/article_500.html http://bims.iranjournals.ir/article_500_37ead49e70ddc70e5d343101a2a9cebe.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 Improvements of two preconditioned AOR iterative methods for Z-matrices 357 371 EN Mohsen Hasani Islamic Azad University hasani.mo@gmail.com Davod Khojasteh Salkuyeh University of Guilan salkuyeh@gmail.com ‎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 http://bims.iranjournals.ir/article_501.html http://bims.iranjournals.ir/article_501_8a1c873672368b347de367b050646428.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 Ostrowski type inequalities for functions whose derivatives are preinvex 373 386 EN Imdat Işcan Giresun University imdat.iscan@giresun.edu.tr 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 http://bims.iranjournals.ir/article_502.html http://bims.iranjournals.ir/article_502_aa3a54cac93833e16043e4a243cffb1f.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 On the decomposable numerical range of operators 387 398 EN Yousef Zamani Sahand University of Technology zamani@sut.ac.ir Sima Ahsani Sahand University of Technology s-ahsani@sut.ac.ir  ‎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 http://bims.iranjournals.ir/article_503.html http://bims.iranjournals.ir/article_503_b7e2e3cc8e6d67d8124fdf498d842b65.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 WZ factorization via Aba y-Broyden-Spedicato algorithms 399 411 EN Effat Golpar-Raboky null University of Qom g_raboky@yahoo.com N. Mahdavi-Amiri null Sharif University of Technology nezamm@sharif.edu 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 http://bims.iranjournals.ir/article_504.html http://bims.iranjournals.ir/article_504_cc2f035a33cf3308b3f1d82d42cd6624.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 A graphical difference between the inverse and regular semigroups 413 421 EN Ayoub Gharibkhajeh Islamic Azad university North-Tehran Branch a_gharib@iau-tnb.ac.ir Hossein Doostie Science and Research, Islamic Azad University Tehran- Iran doostih@tmu.ac.ir 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 http://bims.iranjournals.ir/article_505.html http://bims.iranjournals.ir/article_505_8d4a7f029daec49b029448a7f5252b20.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 Gorenstein global dimensions for Hopf algebra actions 423 431 EN Qunxing Pan Department of Mathematics, Nanjing Agricultural University pqxjs98@njau.edu.cn Faqun Cai Department of Economic Management, Nanjing College of Chemical Technology cfq1217@163.com 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 http://bims.iranjournals.ir/article_506.html http://bims.iranjournals.ir/article_506_9440f67571725993f34bcd0d32f3296c.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 \$(m,n)\$-algebraically compactness and \$(m,n)\$-pure injectivity 433 445 EN Mahmood Behboodi Isfahan University of Technology mbehbood@cc.iut.ac.ir Atefeh Ghorbani Isfahan University of Technology a_ghorbani@cc.iut.ac.ir Seyed Hossein Shojaee Isfahan university of technology hshojaee@math.iut.ac.ir 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 http://bims.iranjournals.ir/article_507.html http://bims.iranjournals.ir/article_507_09d25bec7f5a7b3bdf5caa983c9d38ba.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 A Stochastic algorithm to solve multiple dimensional Fredholm integral equations of the second kind 447 458 EN Rahman Farnoosh School of Mathematics, Iran University of Science and Technology. rfarnoosh@iust.ac.ir Mahboubeh Aalaei School of Mathematics, Iran University of Science and Technology. aalaei@iust.ac.ir 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 http://bims.iranjournals.ir/article_508.html http://bims.iranjournals.ir/article_508_c94cabec98592f562c8a3e4567221f96.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 On \$I\$-statistical and \$I\$-lacunary statistical convergence of order \$alpha\$ 459 472 EN Pratulananda Das Jadavpour University pratulananda@yahoo.co.in Ekrem Savas Istanbul Commerce University ekremsavas@yahoo.com 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<alpha< 1\$‎. ‎We mainly investigate their‎ ‎relationship and also make some observations about these classes‎ ‎and in the way try to give an answer to an open problem posed By‎ ‎Das‎, ‎Savas and Ghosal in 2011‎. ‎The study leaves a lot of‎ ‎interesting open problems‎. I-statistical convergence,I-lacunary statistical convergence,statistical convergence of order \$alpha\$ http://bims.iranjournals.ir/article_509.html http://bims.iranjournals.ir/article_509_fe820582c3d031263737aa3b6e5a7007.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 A characterization of the symmetric group of prime degree 473 480 EN Qingliang Zhang School of Sciences, Nantong University, 226007, Nantong, P. R. China qingliangstudent@163.com Jinhua Wang School of Sciences, Nantong University, 226007, Nantong, P. R. China jhwang@ntu.edu.cn Weijun Liu School of Sciences, Nantong University, 226007, Nantong, P. R. China wjliu6210@126.com 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 http://bims.iranjournals.ir/article_510.html http://bims.iranjournals.ir/article_510_dee5dd7e5a3f35385b5ddbc71bf0cc1b.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 Approximating fixed points of nonexpansive mappings and solving systems of variational inequalities 481 504 EN Hossein Piri Department of Mathematics, University of Bonab, Bonab 5551761167, Iran hossein_piri1979@yahoo.com ‎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 http://bims.iranjournals.ir/article_511.html http://bims.iranjournals.ir/article_511_d0c5befcc72c8fd3470d89ccbd4d2ba3.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 Arens regularity of bilinear forms and unital Banach module spaces 505 520 EN kazem Haghnejad Azar Faculty member of Mohghegh Ardabili Universsity haghnejadmath@yahoo.com 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 http://bims.iranjournals.ir/article_512.html http://bims.iranjournals.ir/article_512_7cc3f3725b7b3c1fe554083605917069.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 Weak Banach-Saks property in the space of compact operators 521 530 EN B. Khadijeh Moosavi Islamic Azad University, Bafgh Branch khmosavi@gmail.com S. Mohammad Moshtaghioun Yazd University moshtagh90@gmail.com 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 http://bims.iranjournals.ir/article_513.html http://bims.iranjournals.ir/article_513_d1178361f94ff0d658d4159f2e3bc59b.pdf
Iranian Mathematical Society (IMS) Bulletin of the Iranian Mathematical Society 1017-060X 1735-8515 40 2 2014 04 01 On generalisations of almost prime and weakly prime ideals 531 540 EN Mahdieh Ebrahimpour ‎University ‎of Vali-e-Asr mahdieh_ebrahimpour@yahoo.com Let \$R\$ be a commutative ring with identity‎. ‎A proper ideal \$P\$ of \$R\$ is a<n> \$(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 http://bims.iranjournals.ir/article_514.html http://bims.iranjournals.ir/article_514_6d6ae9529874c4c6f84dc631664e5962.pdf