ORIGINAL_ARTICLE Common fixed points of f-weak contractions in cone metric spaces Recently, Choudhury and Metiya [Fixed points of weak contractions in cone metric spaces, Nonlinear Analysis 72 (2010) 1589-1593] proved some fixed point theorems for weak contractions in cone metric spaces. Weak contractions are generalizations of the Banach's contraction mapping, which have been studied by several authors. In this paper, we introduce the notion of \$f\$-weak contractions and also establish a coincidence and common fixed point result for \$f\$-weak contractions in cone metric spaces. Our result is supported by an example which include and generalize the results of Choudhury and Metiya's work. http://bims.iranjournals.ir/article_218_d595625aa45af7f415864e2b1458807a.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 293 303 Cone metric spaces Weak contraction f-weak contraction coincidence point common fixed point Wultipol Sintunavarat poom_teun@hotmail.com true 1 King Mongkut's University of Technology Thonburi (KMUTT) King Mongkut's University of Technology Thonburi (KMUTT) King Mongkut's University of Technology Thonburi (KMUTT) AUTHOR Poom Kumam poom.kum@kmutt.ac.th true 2 King Mongkut's University of Technology Thonburi (KMUTT) King Mongkut's University of Technology Thonburi (KMUTT) King Mongkut's University of Technology Thonburi (KMUTT) LEAD_AUTHOR
ORIGINAL_ARTICLE Rings with a setwise polynomial-like condition Let \$R\$ be an infinite ring. Here we prove that if \$0_R\$ belongs to \${x_1x_2cdots x_n ;|; x_1,x_2,dots,x_nin X}\$ for every infinite subset \$X\$ of \$R\$, then \$R\$ satisfies the polynomial identity \$x^n=0\$. Also we prove that if \$0_R\$ belongs to \${x_1x_2cdots x_n-x_{n+1} ;|; x_1,x_2,dots,x_n,x_{n+1}in X}\$ for every infinite subset \$X\$ of \$R\$, then \$x^n=x\$ for all \$xin R\$. http://bims.iranjournals.ir/article_231_c96d633637c016b61c15d2693daeeffb.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 305 311 Primitive rings Polynomial identities Combinatorial conditions Ali Tavakoli ali_tavakoli_targhi@yahoo.com true 1 Islamic Azad University - Majlesi Branch Islamic Azad University - Majlesi Branch Islamic Azad University - Majlesi Branch AUTHOR Alireza Abdollahi a.abdollahi@math.ui.ac.ir true 2 University of Isfahan University of Isfahan University of Isfahan LEAD_AUTHOR Howard E. Bell hbell@brocku.ca true 3 Brock University Brock University Brock University AUTHOR
ORIGINAL_ARTICLE A new family in the stable homotopy groups of spheres Let \$p\$ be a prime number greater than three. In this paper, we prove the existence of a new family of homotopy elements in the stable homotopy groups of spheres \$pi_{ast}(S)\$ which is represented by \$h_nh_mtilde{beta}_{s+2}in {rm Ext}_A^{s+4, q[p^n+p^m+(s+2)p+(s+1)]+s}(mathbb{Z}_p,mathbb{Z}_p)\$ up to nonzero scalar in the Adams spectral sequence, where \$ngeq m+2>5\$, \$0leq sExt}_A^{s+2,q[(s+2)p+(s+1)]+s}(mathbb{Z}_p,mathbb{Z}_p)\$ was defined by X. Wang and Q. Zheng. http://bims.iranjournals.ir/article_204_3e0a128f7a5b367bd3351fe6549af39e.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 313 322 stable homotopy groups of spheres Adams spectral sequence May spectral sequence Xiugui Liu xgliu@nankai.edu.cn true 1 School of Mathematical Sciences and LPMC, Nankai University, Tianjin 300071, P. R China School of Mathematical Sciences and LPMC, Nankai University, Tianjin 300071, P. R China School of Mathematical Sciences and LPMC, Nankai University, Tianjin 300071, P. R China LEAD_AUTHOR Kai Ma kai-ma@163.com true 2 Mathematics and Information Science College,Hebei Normal University, 050016,Shijiazhuang, P. R. China Mathematics and Information Science College,Hebei Normal University, 050016,Shijiazhuang, P. R. China Mathematics and Information Science College,Hebei Normal University, 050016,Shijiazhuang, P. R. China AUTHOR
ORIGINAL_ARTICLE Branches in random recursive k-ary trees In this paper, using generalized {polya} urn models we find the expected value of the size of a branch in recursive \$k\$-ary trees. We also find the expectation of the number of nodes of a given outdegree in a branch of such trees. http://bims.iranjournals.ir/article_200_0fb18b5d341305095aa3c67a34c101b0.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 323 331 trees random recursive trees generalized P'olya urn models Mehri Javanian javanian_m@yahoo.com true 1 Javanian Javanian Javanian AUTHOR Mohammad Q. Vahidi Asl m-vahidi@sbu.ac.ir true 2 Vahidi-Asl Vahidi-Asl Vahidi-Asl LEAD_AUTHOR
ORIGINAL_ARTICLE Horvitz-Thompson estimator of population mean under inverse sampling designs Inverse 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 unbiased estimator, corresponding to post-stratification approach. Both of these are not location-invariant, but this is ignorable for alternative estimator. 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.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 333 347 Finite Population Inverse Sampling Post-stratification Random Sample Size Mohammad Mohammadi m.mohammadi@sci.ui.ac.ir true 1 School of Mathematical Science, Isfahan University of Technology, Isfahan, Iran. School of Mathematical Science, Isfahan University of Technology, Isfahan, Iran. School of Mathematical Science, Isfahan University of Technology, Isfahan, Iran. LEAD_AUTHOR Mohammad Salehi Marzijarani salehi_m@cc.iut.ac.ir true 2 Department of Mathematical Sciences, Isfahan University of Technology 84156-83111, Iran; Department of Mathematics, Statistics and Physics, Qatar University, P.O.Box 2713, Doha, Qatar. Department of Mathematical Sciences, Isfahan University of Technology 84156-83111, Iran; Department of Mathematics, Statistics and Physics, Qatar University, P.O.Box 2713, Doha, Qatar. Department of Mathematical Sciences, Isfahan University of Technology 84156-83111, Iran; Department of Mathematics, Statistics and Physics, Qatar University, P.O.Box 2713, Doha, Qatar. AUTHOR
ORIGINAL_ARTICLE Comparison results on the preconditioned mixed-type splitting iterative method for M-matrix linear systems Consider the linear system Ax=b where the coefficient matrix A is an M-matrix. In the present work, it is proved that the rate of convergence of the Gauss-Seidel method is faster than the mixed-type splitting and AOR (SOR) iterative methods for solving M-matrix linear systems. Furthermore, we improve the rate of convergence of the mixed-type splitting iterative method by applying a preconditioned matrix. Comparison theorems show that the rate of convergence of the preconditioned Gauss-Seidel method is faster than the preconditioned mixed-type splitting and AOR (SOR) iterative methods. Finally, some numerical examples are presented to illustrate the reality of our comparison theorems. http://bims.iranjournals.ir/article_211_dc5b9e9e1b2a179a471b622100c26a58.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 349 367 Linear systems Mixed-type splitting iterative method Preconditioned matrix M-matrix M. Mohseni Moghadam mohseni@mail.uk.ac.ir true 1 Shahid Bahonar University of Kerman Shahid Bahonar University of Kerman Shahid Bahonar University of Kerman AUTHOR Fatemeh Panjeh Ali Beik f.beik@vru.ac.ir true 2 Vali-Asr University of Rafsanjan Vali-Asr University of Rafsanjan Vali-Asr University of Rafsanjan LEAD_AUTHOR
ORIGINAL_ARTICLE An iterative method for amenable semigroup and infinite family of non expansive mappings in Hilbert spaces begin{abstract} In this paper, we introduce an iterative method for amenable semigroup of non expansive mappings and infinite family of non expansive mappings in the frame work of Hilbert spaces. We prove the strong convergence of the proposed iterative algorithm to the unique solution of a variational inequality, which is the optimality condition for a minimization problem. The results presented in this paper mainly extend the corresponding results announced by Qin et al. [X. Qin, Y. J. Cho, and S. M. Kang, An iterative method for an infinite family of non-expansive mappings in Hilbert spaces, Bull. Malays. Math. Sci. Soc. 32 (2009) 161-171] and many others. end{abstract} http://bims.iranjournals.ir/article_207_7d5d8ff16fbbbca2e1790a0f9ab74c87.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 369 389 common fixed point strong convergence Amenable semigroup Husain Piri husain.piri@gmail.com true 1 Department of Mathematics, Bonab Higher Education Complex Department of Mathematics, Bonab Higher Education Complex Department of Mathematics, Bonab Higher Education Complex LEAD_AUTHOR Hamid Vaezi hvaezi@tabrizu.ac.ir true 2 Faculty of Mathematical Sciences University of Tabriz, Tabriz, Iran Faculty of Mathematical Sciences University of Tabriz, Tabriz, Iran Faculty of Mathematical Sciences University of Tabriz, Tabriz, Iran AUTHOR
ORIGINAL_ARTICLE Recurrent metrics in the geometry of second order differential equations Given a pair (semispray \$S\$, metric \$g\$) on a tangent bundle, the family of nonlinear connections \$N\$ such that \$g\$ is recurrent with respect to \$(S, N)\$ with a fixed recurrent factor is determined by using the Obata tensors. In particular, we obtain a characterization for a pair \$(N, g)\$ to be recurrent as well as for the triple \$(S, stackrel{c}{N}, g)\$ where \$stackrel{c}{N}\$ is the canonical nonlinear connection of the semispray \$S\$. Also, the Weyl connection of conformal gauge theories is obtained as a particular case. http://bims.iranjournals.ir/article_215_dcd58d4931f7da614e2cbc66aa27cade.pdf 2011-02-23T11:23:20 2019-06-17T11:23:20 391 401 Semispray nonlinear connection recurrent metric Obata operators Mircea Crasmareanu mcrasm@uaic.ro true 1 Faculty of Mathematics University "Al. I. Cuza" Iasi, 700506 Faculty of Mathematics University "Al. I. Cuza" Iasi, 700506 Faculty of Mathematics University "Al. I. Cuza" Iasi, 700506 LEAD_AUTHOR
ORIGINAL_ARTICLE Projective maximal submodules of extending regular modules We show  that a projective maximal submodule of afinitely generated, regular, extending module is a directsummand. Hence, every finitely generated, regular, extendingmodule with projective maximal submodules is semisimple. As aconsequence, we observe that every regular, hereditary, extendingmodule is semisimple. This generalizes and simplifies a result of  Dung and   Smith. As another consequence, we observe thatevery right continuous ring, whose maximal right ideals areprojective, is semisimple Artinian. This generalizes some resultsof   Osofsky and   Karamzadeh. We also observe thatfour classes of rings, namely right \$\aleph_0\$-continuous rings,right continuous rings, right \$\aleph_0\$-continuous regular ringsand right continuous regular rings are not axiomatizable. http://bims.iranjournals.ir/article_407_6a4d7f84d031275eb5d254f9f2871b8d.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 403 412 continuous rings extending rings regular rings aleph_0-self-injective rings E. Momtahan true 1 Yasouj University Yasouj University Yasouj University LEAD_AUTHOR
ORIGINAL_ARTICLE Finite p-groups with few non-linear irreducible character kernels Abstract. 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.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 413 422 Minimal normal subgroups few character kernels strong and weak conditions Hossein Doostie doostih@tmu.as.ir true 1 Tarbiat Moallem University Tarbiat Moallem University Tarbiat Moallem University AUTHOR Amin Saeidi saeidi.amin@gmail.com true 2 Tarbiat Moallem University Tarbiat Moallem University Tarbiat Moallem University LEAD_AUTHOR
ORIGINAL_ARTICLE Invariance of the barycentric subdivision of a simplicial complex ‎In this paper we prove that a simplicial complex is determined‎ ‎uniquely up to isomorphism by its barycentric subdivision as well as‎ ‎its comparability graph‎. ‎We also put together several algebraic‎, ‎combinatorial and topological invariants of simplicial complexes‎. http://bims.iranjournals.ir/article_212_de5bc8c7b7b3dc3bfb85ee068f5d21f6.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 423 432 ‎Simplicial complex‎ ‎comparability graph‎ ‎barycentric subdivision Rashid Zaare-Nahandi rashidzn@iasbs.ac.ir true 1 Institute for Advanced Studies in Basic Sciences Institute for Advanced Studies in Basic Sciences Institute for Advanced Studies in Basic Sciences LEAD_AUTHOR
ORIGINAL_ARTICLE On Rickart modules Let \$R\$ be an arbitrary ring with identity and \$M\$ a right \$R\$-module with \$S=\$ End\$_R(M)\$. The module \$M\$ is called {it Rickart} if for any \$fin S\$, \$r_M(f)=Se\$ for some \$e^2=ein S\$. We prove that some results of principally projective rings and Baer modules can be extended to Rickart modules for this general settings. http://bims.iranjournals.ir/article_209_a482f3c0119843e2d96bfda7f6af9907.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 433 445 Rickart modules Baer modules reduced modules rigid modules S Agayev true 1 Eropean University of Lefke, Cyprus Eropean University of Lefke, Cyprus Eropean University of Lefke, Cyprus AUTHOR S Halicioglu halici@ankara.edu.tr true 2 Department of Mathematics Ankara University Department of Mathematics Ankara University Department of Mathematics Ankara University LEAD_AUTHOR A Harmanci true 3 Hacettepe University, Turkey Hacettepe University, Turkey Hacettepe University, Turkey AUTHOR
ORIGINAL_ARTICLE Optimal order finite element approximation for a hyperbolic‎ ‎integro-differential equation ‎Semidiscrete finite element approximation of a hyperbolic type‎ ‎integro-differential equation is studied. The model problem is‎ ‎treated as the wave equation which is perturbed with a memory term.‎ ‎Stability estimates are obtained for a slightly more general problem.‎ ‎These, based on energy method, are used to prove optimal order‎ ‎a priori error estimates.‎ http://bims.iranjournals.ir/article_201_e72a83b9b71c31f92537ef2e58b72810.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 447 459 finite element method wave equation ‎ ‎integro-differential equation Stability a priori error estimate Fardin Saedpanah f_saedpanah@yahoo.com true 1 University of Kurdistan, Department of Mathematics University of Kurdistan, Department of Mathematics University of Kurdistan, Department of Mathematics LEAD_AUTHOR
ORIGINAL_ARTICLE Properties of multivalent functions associated with certain integral operator Let 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.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 461 468 Multivalent function analytic function integral operator Jin-Lin Liu jlliu@yzu.edu.cn true 1 Department of Mathematics, Yangzhou University Department of Mathematics, Yangzhou University Department of Mathematics, Yangzhou University LEAD_AUTHOR
ORIGINAL_ARTICLE Applications of epi-retractable modules An 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.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 469 477 Epi-retractable modules semi-simple rings Perfect rings Hereditary rings von-Numann regular rings Bashishth Pandeya bmpandeya@bhu.ac.in true 1 Department of Applied Mathematics, Institute of Technology, Banaras Hindu University, Varanasi-221005, India. Department of Applied Mathematics, Institute of Technology, Banaras Hindu University, Varanasi-221005, India. Department of Applied Mathematics, Institute of Technology, Banaras Hindu University, Varanasi-221005, India. AUTHOR Avanish Chaturvedi akc99@rediffmail.com true 2 Department of Mathematics, Jaypee Institute of Information Technology, (Deemed University) A-10, Sector-62, Noida-201307 (UP), India Department of Mathematics, Jaypee Institute of Information Technology, (Deemed University) A-10, Sector-62, Noida-201307 (UP), India Department of Mathematics, Jaypee Institute of Information Technology, (Deemed University) A-10, Sector-62, Noida-201307 (UP), India LEAD_AUTHOR Ashok Gupta ashokg@bhu.ac.in true 3 Department of Applied Mathematics, Institute of Technology, Banaras Hindu University, Varanasi-221005, India. Department of Applied Mathematics, Institute of Technology, Banaras Hindu University, Varanasi-221005, India. Department of Applied Mathematics, Institute of Technology, Banaras Hindu University, Varanasi-221005, India. AUTHOR
ORIGINAL_ARTICLE Some vector fields on a riemannian manifold with semi-symmetric metric connection In 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.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 479 490 Semi-symmetric metric connection sectional curvature conformally flat manifold pseudo symmetric manifold concircular vector field Füsun Özen Zengin fozen@itu.edu.tr true 1 Istanbul Technical University Istanbul Technical University Istanbul Technical University LEAD_AUTHOR Sezgin Altay Demirbag saltay@itu.edu.tr true 2 Istanbul Technical University Istanbul Technical University Istanbul Technical University AUTHOR S. Aynur Uysal auysal@dogus.edu.tr true 3 Dogus University Dogus University Dogus University AUTHOR Hülya Bagdatli Yilmaz hbagdatli@marmara.edu.tr true 4 Marmara University Marmara University Marmara University AUTHOR
ORIGINAL_ARTICLE Riordan group approaches in matrix factorizations In 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 in nite generalized Pascal matrix in terms of this new matrix, using a Riordan group approach. Further some interesting results and applications are derived. http://bims.iranjournals.ir/article_205_da5f4f10d7f10a4b73c7db3f21ccb967.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 491 506 Riordan Group Factorization Binary Recurrences Pascal Matrix Emrah Kilic ekilic@etu.edu.tr true 1 TOBB University of Economics and Technology Mathematics Department TOBB University of Economics and Technology Mathematics Department TOBB University of Economics and Technology Mathematics Department LEAD_AUTHOR Nese Omur neseomur@kocaeli.edu.tr true 2 Kocaeli University Mathematics Department Kocaeli University Mathematics Department Kocaeli University Mathematics Department AUTHOR Gulfer Tatar gulfera@kocaeli.edu.tr true 3 Kocaeli University Mathematics Department Kocaeli University Mathematics Department Kocaeli University Mathematics Department AUTHOR
ORIGINAL_ARTICLE Some homological properties of amalgamated duplication of a ring along an ideal In this work, we investigate the transfer of some homological properties from a ring \$R\$ to its amalgamated duplication along some ideal \$I\$ of \$R\$ \$Rbowtie I\$, and then generate new and original families of rings with these properties. http://bims.iranjournals.ir/article_210_485789e3f153661d4d8c1136c73cb0d1.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 507 515 Amalgamated Perfect ring (n d)-ring Mohamed Chhiti chhiti.med@hotmail.com true 1 University of Fez, Fez, Morocco University of Fez, Fez, Morocco University of Fez, Fez, Morocco AUTHOR Najib Mahdou mahdou@hotmail.com true 2 Department of Mathematics, Faculty of Sciences and Technology, University of Fez, Fez, Morocco. Department of Mathematics, Faculty of Sciences and Technology, University of Fez, Fez, Morocco. Department of Mathematics, Faculty of Sciences and Technology, University of Fez, Fez, Morocco. LEAD_AUTHOR
ORIGINAL_ARTICLE A note on the socle of certain types of f-rings For any reduced commutative \$f\$-ring with identity and bounded inversion, we show that a condition which is obviously necessary for the socle of the ring to coincide with the socle of its bounded part, is actually also sufficient. The condition is that every minimal ideal of the ring consist entirely of bounded elements. It is not too stringent, and is satisfied, for instance, by rings of continuous functions. http://bims.iranjournals.ir/article_214_3c1783bf3988903f43f20700e3e575bc.pdf 2012-07-15T11:23:20 2019-06-17T11:23:20 517 528 frame function rings ideal socle Themba Dube tdube2013@yahoo.co.za true 1 University of South Africa University of South Africa University of South Africa LEAD_AUTHOR
ORIGINAL_ARTICLE Ring structures of mod p equivariant cohomology rings and ring homomorphisms between them In 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 2012-07-15T11:23:20 2019-06-17T11:23:20 529 542 G-manifold equivariant index equivariant cohomology ring homomorphism Yanchang Chen cyc810707@163.com true 1 College of Mathematics and Information Science, Hebei Normal University, Yuhua Road 113, Shijiazhuang 050016, P. R. China College of Mathematics and Information Science, Hebei Normal University, Yuhua Road 113, Shijiazhuang 050016, P. R. China College of Mathematics and Information Science, Hebei Normal University, Yuhua Road 113, Shijiazhuang 050016, P. R. China AUTHOR Yanying Wang wyanying2003@yahoo.com.cn true 2 College of Mathematics and Information Science, Hebei Normal University, Yuhua Road 113, Shijiazhuang 050016, P. R. China College of Mathematics and Information Science, Hebei Normal University, Yuhua Road 113, Shijiazhuang 050016, P. R. China College of Mathematics and Information Science, Hebei Normal University, Yuhua Road 113, Shijiazhuang 050016, P. R. China LEAD_AUTHOR