Springer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Common fixed points of f-weak contractions in cone metric spaces293303218ENWultipolSintunavaratKing Mongkut's University of Technology Thonburi (KMUTT)PoomKumamKing Mongkut's University of Technology Thonburi (KMUTT)Journal Article20100505Recently, Choudhury and Metiya [Fixed points of weak contractions in <br />cone metric spaces, Nonlinear Analysis 72 (2010) 1589-1593] proved <br />some fixed point theorems for weak contractions in cone metric <br />spaces. Weak contractions are generalizations of the Banach's <br />contraction mapping, which have been studied by several authors. In <br />this paper, we introduce the notion of $f$-weak contractions and <br />also establish a coincidence and common fixed point result for <br />$f$-weak contractions in cone metric spaces. Our result is supported <br />by an example which include and generalize the results of Choudhury <br />and Metiya's work.http://bims.iranjournals.ir/article_218_d595625aa45af7f415864e2b1458807a.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Rings with a setwise polynomial-like condition305311231ENAliTavakoliIslamic Azad University - Majlesi BranchAlirezaAbdollahiUniversity of IsfahanHoward E.BellBrock UniversityJournal Article20100420Let $R$ be an infinite ring. Here we <br />prove that if $0_R$ belongs to ${x_1x_2cdots x_n ;|; <br />x_1,x_2,dots,x_nin X}$ for every infinite subset $X$ of $R$, <br />then $R$ satisfies the polynomial identity $x^n=0$. Also we prove <br />that if $0_R$ belongs to ${x_1x_2cdots <br />x_n-x_{n+1} ;|; x_1,x_2,dots,x_n,x_{n+1}in X}$ for every <br />infinite subset $X$ of $R$, then $x^n=x$ for all $xin R$.http://bims.iranjournals.ir/article_231_c96d633637c016b61c15d2693daeeffb.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715A new family in the stable homotopy groups of spheres313322204ENXiuguiLiuSchool of Mathematical Sciences and LPMC,
Nankai University,
Tianjin 300071,
P. R ChinaKaiMaMathematics and Information
Science College,Hebei Normal University, 050016,Shijiazhuang, P. R. ChinaJournal Article20100619Let $p$ be a prime number greater than three. In this paper, we <br />prove the existence of a new family of homotopy elements in the <br />stable homotopy groups of spheres $pi_{ast}(S)$ which is <br />represented by $h_nh_mtilde{beta}_{s+2}in {rm Ext}_A^{s+4, <br />q[p^n+p^m+(s+2)p+(s+1)]+s}(mathbb{Z}_p,mathbb{Z}_p)$ up to nonzero <br />scalar in the Adams spectral sequence, where $ngeq m+2>5$, $0leq <br />s<br />Ext}_A^{s+2,q[(s+2)p+(s+1)]+s}(mathbb{Z}_p,mathbb{Z}_p)$ was <br />defined by X. Wang and Q. Zheng.http://bims.iranjournals.ir/article_204_3e0a128f7a5b367bd3351fe6549af39e.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Branches in random recursive k-ary trees323331200ENMehriJavanianJavanianMohammad Q.Vahidi AslVahidi-AslJournal Article20100530In this paper, using generalized {polya} urn <br />models we find the expected value of the size of a branch in <br />recursive $k$-ary trees. We also find the expectation of the <br />number of nodes of a given outdegree in a branch of such <br />trees.http://bims.iranjournals.ir/article_200_0fb18b5d341305095aa3c67a34c101b0.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Horvitz-Thompson estimator of population mean under inverse sampling designs333347255ENMohammadMohammadiSchool of Mathematical Science, Isfahan University of Technology, Isfahan, Iran.MohammadSalehi MarzijaraniDepartment of Mathematical Sciences, Isfahan University of Technology 84156-83111, Iran;
Department of Mathematics, Statistics and Physics, Qatar University, P.O.Box 2713, Doha, Qatar.Journal Article20100325Inverse sampling design is generally considered to be appropriate technique when the population is divided into two subpopulations, one of which contains only few units. In this paper, we derive the Horvitz-Thompson estimator for the population mean under inverse sampling designs, where subpopulation sizes are known. We then introduce an alternative <br /> unbiased estimator, corresponding to post-stratification approach. Both of these are not location-invariant, but this is ignorable for alternative estimator. <br />Using a simulation study, we find that Horvitz-Thompson estimator is an efficient estimator when the mean of the off-interest subpopulation is close to zero while the alternative estimator appears to be an efficient estimator in general.http://bims.iranjournals.ir/article_255_8bc393a21f635d83fc2a4bdda66f1e39.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Comparison results on the preconditioned mixed-type splitting
iterative method for M-matrix linear systems349367211ENM.Mohseni MoghadamShahid Bahonar University of KermanFatemehPanjeh Ali BeikVali-Asr University of RafsanjanJournal Article20100903Consider the linear system Ax=b where the coefficient <br />matrix A is an M-matrix. In the present work, it is proved <br />that the rate of convergence of the Gauss-Seidel method is faster <br />than the mixed-type splitting and AOR (SOR) iterative methods for <br />solving M-matrix linear systems. Furthermore, we improve the rate <br />of convergence of the mixed-type splitting iterative method by <br />applying a preconditioned matrix. Comparison theorems show that <br />the rate of convergence of the preconditioned Gauss-Seidel method <br />is faster than the preconditioned mixed-type splitting and AOR <br />(SOR) iterative methods. Finally, some numerical examples are <br />presented to illustrate the reality of our comparison theorems.http://bims.iranjournals.ir/article_211_dc5b9e9e1b2a179a471b622100c26a58.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715An iterative method for amenable semigroup and infinite family of non expansive mappings
in Hilbert spaces369389207ENHusainPiriDepartment of Mathematics, Bonab Higher Education ComplexHamidVaeziFaculty of Mathematical Sciences University
of Tabriz, Tabriz, IranJournal Article20110225begin{abstract} <br />In this paper, we introduce an iterative method for amenable <br />semigroup of non expansive mappings and infinite family of non <br />expansive mappings in the frame work of Hilbert spaces. We prove the <br />strong convergence of the proposed iterative algorithm to the unique <br />solution of a variational inequality, which is the optimality <br />condition for a minimization problem. The results presented in this <br />paper mainly extend the corresponding results announced by Qin et <br />al. [X. Qin, Y. J. Cho, and S. M. Kang, An iterative method for an <br />infinite family of non-expansive mappings in Hilbert spaces, Bull. <br />Malays. Math. Sci. Soc. 32 (2009) 161-171] and many others. <br /> <br />end{abstract}http://bims.iranjournals.ir/article_207_7d5d8ff16fbbbca2e1790a0f9ab74c87.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220110223Recurrent metrics in the geometry of second order differential equations391401215ENMirceaCrasmareanuFaculty of Mathematics
University "Al. I. Cuza"
Iasi, 700506Journal Article20110209Given a pair (semispray $S$, metric $g$) on a tangent bundle, the <br />family of nonlinear connections $N$ such that $g$ is recurrent <br />with respect to $(S, N)$ with a fixed recurrent factor is <br />determined by using the Obata tensors. In particular, we obtain a <br />characterization for a pair $(N, g)$ to be recurrent as well as <br />for the triple $(S, stackrel{c}{N}, g)$ where $stackrel{c}{N}$ <br />is the canonical nonlinear connection of the semispray $S$. Also, <br />the Weyl connection of conformal gauge theories is obtained as a particular <br />case.http://bims.iranjournals.ir/article_215_dcd58d4931f7da614e2cbc66aa27cade.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Projective maximal submodules of extending regular modules403412407ENE.MomtahanYasouj UniversityJournal Article20090430We show that a projective maximal submodule of a<br />finitely generated, regular, extending module is a direct<br />summand. Hence, every finitely generated, regular, extending<br />module with projective maximal submodules is semisimple. As a<br />consequence, we observe that every regular, hereditary, extending<br />module is semisimple. This generalizes and simplifies a result of<br /> Dung and Smith. As another consequence, we observe that<br />every right continuous ring, whose maximal right ideals are<br />projective, is semisimple Artinian. This generalizes some results<br />of Osofsky and Karamzadeh. We also observe that<br />four classes of rings, namely right $aleph_0$-continuous rings,<br />right continuous rings, right $aleph_0$-continuous regular rings<br />and right continuous regular rings are not axiomatizable.http://bims.iranjournals.ir/article_407_6a4d7f84d031275eb5d254f9f2871b8d.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Finite p-groups with few non-linear irreducible character kernels413422208ENHosseinDoostieTarbiat Moallem UniversityAminSaeidiTarbiat Moallem UniversityJournal Article20090430Abstract. In this paper, we classify all of the ﬁnite p-groups with at most three non linear irreducible character kernels.http://bims.iranjournals.ir/article_208_69f56c704b32022bc49cb06797e62448.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Invariance of the barycentric subdivision of a simplicial complex423432212ENRashidZaare-NahandiInstitute for Advanced Studies in Basic SciencesJournal Article20101025In this paper we prove that a simplicial complex is determined <br />uniquely up to isomorphism by its barycentric subdivision as well as <br />its comparability graph. We also put together several algebraic, <br />combinatorial and topological invariants of simplicial complexes.http://bims.iranjournals.ir/article_212_de5bc8c7b7b3dc3bfb85ee068f5d21f6.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715On Rickart modules433445209ENSAgayevEropean University of Lefke, CyprusSHaliciogluDepartment of Mathematics
Ankara UniversityAHarmanciHacettepe University, TurkeyJournal Article20100926Let $R$ be an arbitrary ring with <br />identity and $M$ a right $R$-module with $S=$ End$_R(M)$. The <br />module $M$ is called {it Rickart} if for any $fin S$, <br />$r_M(f)=Se$ for some $e^2=ein S$. We prove that some results of <br />principally projective rings and Baer modules can be extended to <br />Rickart modules for this general settings.http://bims.iranjournals.ir/article_209_a482f3c0119843e2d96bfda7f6af9907.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Optimal order finite element approximation for a hyperbolic integro-differential equation447459201ENFardinSaedpanahUniversity of Kurdistan,
Department of MathematicsJournal Article20101026Semidiscrete finite element approximation of a hyperbolic type <br />integro-differential equation is studied. The model problem is <br />treated as the wave equation which is perturbed with a memory term. <br />Stability estimates are obtained for a slightly more general problem. <br />These, based on energy method, are used to prove optimal order <br />a priori error estimates.http://bims.iranjournals.ir/article_201_e72a83b9b71c31f92537ef2e58b72810.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Properties of multivalent functions associated with certain integral operator461468198ENJin-LinLiuDepartment of Mathematics, Yangzhou UniversityJournal Article20090705Let A(p) denote the class of functions which are analytic in the open unit disk U. By making use of certain integral operator,we obtain some interesting properties of multivalent analytic functions.http://bims.iranjournals.ir/article_198_05b363674deba2ef06e6925dc08db279.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Applications of epi-retractable modules469477202ENBashishth MuniPandeyaDepartment of Applied Mathematics, Institute of Technology, Banaras Hindu University,
Varanasi-221005, India.Avanish KumarChaturvediDepartment of Mathematics, Jaypee Institute of Information Technology,
(Deemed University) A-10, Sector-62, Noida-201307 (UP), IndiaAshok JiGuptaDepartment of Applied Mathematics, Institute of Technology, Banaras Hindu University,
Varanasi-221005, India.Journal Article20100917An R-module M is called epi-retractable if every submodule of MR is a homomorphic image of M. It is shown that if R is a right perfect ring, then every projective slightly compressible module MR is epi-retractable. If R is a Noetherian ring, then every epi-retractable right R-module has direct sum of uniform submodules. If endomorphism ring of a module MR is von-Neumann regular, then M is semi-simple if and only if M is epi-retractable. If R is a quasi Frobenius ring, then R is a right hereditary ring if and only if every injective right R-module is semi-simple. A ring R is semi-simple if and only if R is right hereditary and every epiretractable right R-module is projective. Moreover, a ring R is semi-simple if and only if R is a pri and von-Neumann regular.http://bims.iranjournals.ir/article_202_388757ddee7a3a67ab050c9a998e2049.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Some vector fields on a riemannian manifold with semi-symmetric metric connection479490203ENFüsunÖzen ZenginIstanbul Technical UniversitySezginAltay DemirbagIstanbul Technical UniversityS. AynurUysalDogus UniversityHülyaBagdatli YilmazMarmara UniversityJournal Article20100719In the first part of this paper, some theorems are given for a Riemannian manifold with semi-symmetric metric connection. In the second part of it, some special vector fields, for example, torse-forming vector fields, recurrent vector fields and concurrent vector fields are examined in this manifold. We obtain some properties of this manifold having the vectors mentioned above.http://bims.iranjournals.ir/article_203_231ecca82cd01017b92531f34000f4d6.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Riordan group approaches in matrix factorizations491506205ENEmrahKilicTOBB University of Economics and Technology Mathematics DepartmentNeseOmurKocaeli University Mathematics DepartmentGulferTatarKocaeli University Mathematics DepartmentJournal Article20090807In this paper, we consider an arbitrary binary polynomial sequence {A_n} and then give a lower triangular matrix representation of this sequence. As main result, we obtain a factorization of the innite generalized Pascal matrix in terms of this new matrix, <br />using a Riordan group approach. Further some interesting results <br />and applications are derived.http://bims.iranjournals.ir/article_205_da5f4f10d7f10a4b73c7db3f21ccb967.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Some homological properties of amalgamated duplication of a ring along an ideal507515210ENMohamedChhitiUniversity of Fez, Fez, MoroccoNajibMahdouDepartment of Mathematics, Faculty of Sciences and Technology, University of Fez, Fez, Morocco.Journal Article20101017In this work, we investigate the transfer of some homological <br />properties from a ring $R$ to its amalgamated duplication along <br />some ideal $I$ of $R$ $Rbowtie I$, and then generate new and <br />original families of rings with these properties.http://bims.iranjournals.ir/article_210_485789e3f153661d4d8c1136c73cb0d1.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715A note on the socle of certain types of f-rings517528214ENThembaDubeUniversity of South AfricaJournal Article20100815For any reduced commutative $f$-ring with identity and bounded <br />inversion, we show that a condition which is obviously necessary for <br />the socle of the ring to coincide with the socle of its bounded <br />part, is actually also sufficient. The condition is that every <br />minimal ideal of the ring consist entirely of bounded elements. It <br />is not too stringent, and is satisfied, for instance, by rings of <br />continuous functions.http://bims.iranjournals.ir/article_214_3c1783bf3988903f43f20700e3e575bc.pdfSpringer and the Iranian Mathematical Society (IMS)Bulletin of the Iranian Mathematical Society1017-060X38220120715Ring structures of mod p equivariant cohomology rings and ring homomorphisms between them529542217ENYanchangChenCollege of Mathematics and Information Science, Hebei Normal University, Yuhua
Road 113, Shijiazhuang 050016, P. R. ChinaYanyingWangCollege of Mathematics and Information Science, Hebei Normal University, Yuhua Road 113, Shijiazhuang 050016, P. R. ChinaJournal Article20101018In this paper, we consider a class of connected oriented (with respect to Z/p) closed G-manifolds with a non-empty finite fixed point set, each of which is G-equivariantly formal, where G = Z/p and p is an odd prime. Using localization theorem and equivariant index, we give an explicit description of the mod p equivariant cohomology ring of such a G-manifold in terms of algebra. This makes it possible to determine the number of equivariant cohomology rings (up to isomorphism) of such 2-dimensional G-manifolds. Moreover, we obtain a description of the ring homomorphism between equivariant cohomology rings of such two G-manifolds induced by a G-equivariant map, and show a characterization of the ring homomorphism.http://bims.iranjournals.ir/article_217_d78bd5727580f199e3b327f8189d5d8a.pdf