2018-05-24T16:25:00Z
http://bims.iranjournals.ir/?_action=export&rf=summon&issue=94
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Bulletin of the Iranian Mathematical Society
2017
10
01
http://bims.iranjournals.ir/article_1182_5ac9306f6f518d1cfe3b1d5c6017a997.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Benson's algorithm for nonconvex multiobjective problems via nonsmooth Wolfe duality
N.
Shafiei
In this paper, we propose an algorithm to obtain an approximation set of the (weakly) nondominated points of nonsmooth multiobjective optimization problems with equality and inequality constraints. We use an extension of the Wolfe duality to construct the separating hyperplane in Benson's outer algorithm for multiobjective programming problems with subdifferentiable functions. We also formulate an infinitive approximation set of the (weakly) nondominated points of biobjective optimization problems. Moreover, we provide some numerical examples to illustrate the advantage of our algorithm.
Multiobjective optimization
approximation algorithm
efficient solution
nondominated point
2017
10
31
975
994
http://bims.iranjournals.ir/article_968_b6e2e95fca85f00c6ce71f96f05c8755.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Critical fixed point theorems in Banach algebras under weak topology features
A.
Ben Amar
A.
Tlili
In this paper, we establish some new critical fixed point theorems for the sum $AB+C$ in a Banach algebra relative to the weak topology, where $frac{I-C}{A}$ allows to be noninvertible. In addition, a special class of Banach algebras will be considered.
Banach algebras
sequentially weakly continuous operators
weakly compact operators
fixed point theorems
2017
10
01
995
1015
http://bims.iranjournals.ir/article_969_4886e0d3f5d96cd35afe9f7650d8511a.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
On annihilator ideals in skew polynomial rings
M.
Zahiri
A.
Moussavi
R.
Mohammadi
This article examines annihilators in the skew polynomial ring $R[x;alpha,delta]$. A ring is strongly right $AB$ if everynon-zero right annihilator is bounded. In this paper, we introduce and investigate a particular class of McCoy rings which satisfy Property ($A$) and the conditions asked by P.P. Nielsen. We assume that $R$ is an ($alpha$,$delta$)-compatible ring, and prove that, if $R$ is nil-reversible then the skew polynomial ring $R[x;alpha,delta]$is strongly right $AB$. It is also shown that, every right duo ring with an automorphism $alpha$ is skew McCoy. Moreover, if $R$ is strongly right $AB$ and skew McCoy, then $R[x;alpha]$ and $R[x;delta]$ have right Property ($A$).
McCoy ring
strongly right $AB$ ring
nil-reversible ring
rings with Property$(A)$
2017
10
01
1017
1036
http://bims.iranjournals.ir/article_977_1616b5a37d6d745579be166ecbf55aa5.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
The norm of pre-Schwarzian derivatives on bi-univalent functions of order $alpha$
H.
Rahmatan
Sh.
Najafzadeh
A.
Ebadian
In the present investigation, we give the best estimates for the norm of the pre-Schwarzian derivative $ T_{f}(z)=dfrac{f^{''}(z)}{f^{'}(z)} $ for bi-starlike functions and a new subclass of bi-univalent functions of order $ alpha $, where $Vert T_{f} Vert= sup_{|z|
Bi-Univalent Functions
bi-starlike functions
subordina- tion
pre-Schwarzian derivatives
2017
10
01
1037
1043
http://bims.iranjournals.ir/article_976_ceb99544ec2644d892bcda3f82707ac5.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Order-type existence theorem for second order nonlocal problems at resonance
F.
Wang
S.
Zhang
This paper gives an abstract order-type existence theorem for second order nonlocal boundary value problems at resonance and obtain existence criteria for at least two positive solutions, where $f$ is a continuous function. Our results generalize or extend related results in the literature and give a positive answer to the question raised in the literature. An example is given to illustrate the new results.
Order-type existence theorem
nonlocal problems
at resonance
2017
10
31
1045
1055
http://bims.iranjournals.ir/article_982_06ecbd0ed0da60644d8ee47c4455ce32.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Existence and blow-up of solution of Cauchy problem for the sixth order damped Boussinesq equation
Y.
Wang
In this paper, we consider the existence and uniqueness of the global solution for the sixth-order damped Boussinesq equation. Moreover, the finite-time blow-up of the solution for the equation is investigated by the concavity method.
Boussinesq equation
Cauchy problem
global solution
blow-up
2017
10
01
1057
1071
http://bims.iranjournals.ir/article_986_575661a92891f4b8f65f2661f90638e1.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Diagonal arguments and fixed points
A.
Karimi
S.
Salehi
A universal schema for diagonalization was popularized by N.S. Yanofsky (2003), based on a pioneering work of F.W. Lawvere (1969), in which the existence of a (diagonolized-out and contradictory) object implies the existence of a fixed-point for a certain function. It was shown that many self-referential paradoxes and diagonally proved theorems can fit in that schema. Here, we fit more theorems in the universal
schema of diagonalization, such as Euclid's proof for the infinitude of the primes and new proofs of G.~Boolos (1997) for Cantor's theorem on the non-equinumerosity of a set with its powerset. Then, in Linear Temporal Logic, we show the non-existence of a fixed-point in this logic whose proof resembles the argument of Yablo's paradox (1985, 1993). Thus, Yablo's paradox turns for the first time into a genuine mathematico-logical theorem in the framework of Linear Temporal Logic. Again the diagonal schema of the paper is used in this proof; and it is also shown that G.~Priest's inclosure schema (1997) can fit in our universal diagonal/fixed-point schema. We also show the existence of dominating (Ackermann-like) functions (which dominate a given countable set of functions, such as primitive recursive functions) in the schema.
Diagonal argument
self-reference
fixed-points
Yablo's paradox
(linear) temporal logic
2017
10
01
1073
1088
http://bims.iranjournals.ir/article_979_53591d674b4feba06d0832b6aca66445.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
On two classes of third order boundary value problems with finite spectrum
J.J.
Ao
The spectral analysis of two classes of third order boundary value problems is investigated. For every positive integer $m$ we construct two classes of regular third order boundary value problems with at most $2m+1$ eigenvalues, counting multiplicity. These kinds of finite spectrum results are previously known only for even order boundary value problems.
Eigenvalues
finite spectrum
third order boundary value problems
2017
10
01
1089
1099
http://bims.iranjournals.ir/article_987_66c828371116cf5ebbb08bd5f732ce45.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Affinization of Segre products of partial linear spaces
K.
Petelczyc
M.
Żynel
Hyperplanes and hyperplane complements in the Segre product of partial linear spaces are investigated. The parallelism of such a complement is characterized in terms of the point-line incidence. Assumptions, under which the automorphisms of the complement are the restrictions of the automorphisms of the ambient space, are given. An affine covering for the Segre product of Veblenian gamma spaces is established. A general construction that produces non-degenerate hyperplanes in the Segre product of partial linear spaces embeddable into projective space is introduced.
Segre product
hyperplane
hyperplane complement
2017
10
31
1101
1126
http://bims.iranjournals.ir/article_1010_ae91b745ca8ce73d8145c9d0ba456580.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
A new one-step iterative process for approximating common fixed points of a countable family of quasi-nonexpansive multi-valued mappings in CAT(0) spaces
S.
Suantai
B.
Panyanak
W.
Phuengrattana
In this paper, we propose a new one-step iterative process for a countable family of quasi-nonexpansive multi-valued mappings in a CAT(0) space. We also prove strong and $Delta$-convergence theorems of the proposed iterative process under some control conditions. Our main results extend and generalize many results in the literature.
Fixed point
quasi-nonexpansive multi-valued mappings
CAT(0) spaces
2017
10
01
1127
1141
http://bims.iranjournals.ir/article_1011_ad0166654aaff419b6748b7e8ebe5cc1.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
A new characterization of $L_2(q)$ by the largest element orders
Q.H.
Jiang
C.G.
Shao
W.J.
Shi
Q.L.
Zhang
We characterize the finite simple groups $L_2(q)$ by the group orders and the largest element orders, where $q$ is a prime or $q=2^a$, with $2^a+1$ or $2^a-1$ a prime.
Finite groups
group orders
largest element orders
characterization
2017
10
31
1143
1151
http://bims.iranjournals.ir/article_1012_732dd4983f33557e48c7c70587b76a1e.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
A radical extension of the category of $S$-sets
M.
Haddadi
M.M.
Ebrahimi
Let S-Set be the category of $S$-sets, sets together with the actions of a semigroup $S$ on them. And, let S-Pos be the category of $S$-posets, posets together with the actions compatible with the orders on them. In this paper we show that the category S-Pos is a radical extension of S-Set; that is there is a radical on the category S-Pos, the order desolator radical, whose torsion-free class is S-Set. To do this, first we give a precise definition of a radical on the category S-Posand construct some functors between the above mentioned categories and finally we show that S-Pos is a radical extension of S-Set.
Radical
$S$-set
$S$-poset
2017
10
31
1153
1163
http://bims.iranjournals.ir/article_1013_e39fbaec4f209d34b2b2b5b8fbbd286c.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
A numerical method for discrete fractional--order chemostat model derived from nonstandard numerical scheme
M.
Zeinadini
M.
Namjoo
In this paper, the fractional--order form of three dimensional chemostat model with variable yields is introduced. The stability analysis of this fractional system is discussed in detail. In order to study the dynamic behaviours of the mentioned fractional system, the well known nonstandard (NSFD) scheme is implemented. The proposed NSFD scheme is compared with the forward Euler and fourth order Runge--Kutta methods. Numerical results show that the NSFD approach is easy and accurate when applied to fractional--order chemostat model.
Chemostat model
fractional--order differential equation
stability
nonstandard finite difference scheme.
2017
10
31
1165
1182
http://bims.iranjournals.ir/article_1014_2be3d0cd976cadfa26b020f52d794dd0.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
On characterizations of hyperbolic harmonic Bloch and Besov spaces
X.
Fu
We define hyperbolic harmonic $omega$-$alpha$-Bloch space $mathcal{B}_omega^alpha$ in the unit ball $mathbb{B}$ of ${mathbb R}^n$ and characterize it in terms of $$frac{omegabig((1-|x|^2)^{beta}(1-|y|^2)^{alpha-beta}big)|f(x)-f(y)|}{[x,y]^gamma|x-y|^{1-gamma}},$$ where $0leq gammaleq 1$. 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.
Hyperbolic harmonic function
Bloch space
Besov space
majorant.
2017
10
31
1183
1194
http://bims.iranjournals.ir/article_1015_68f6233a41b79a34a80bb13734f8caa1.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
On the character space of Banach vector-valued function algebras
M.
Abtahi
Given a compact space $X$ and a commutative Banach algebra $A$, the character spaces of $A$-valued function algebras on $X$ are investigated. The class of natural $A$-valued function algebras, those whose characters can be described by means of characters of $A$ and point evaluation homomorphisms, is introduced and studied. For an admissible Banach $A$-valued function algebra $mathscr{A}$ on $X$, conditions under which the character space $mathfrak{M}(mathscr{A})$ is homeomorphic to $mathfrak{M}(mathfrak{A})times mathfrak{M}(A)$ are presented, where $mathfrak{A}=C(X) capmathscr{A}$ is the subalgebra of $mathscr{A}$ consisting of scalar-valued functions. An illustration of the results is given by some examples.
Commutative Banach algebras
Banach function algebras
vector-valued function algebras
vector-valued characters
2017
10
31
1195
1207
http://bims.iranjournals.ir/article_1016_ddcd6ea7621867940cd31a351db4ee09.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
On some generalized recurrent manifolds
A.A.
Shaikh
I.
Roy
H.
Kundu
The object of the present paper is to introduce and study a type of non-flat semi-Riemannian manifolds, called, super generalized recurrent manifolds which generalizes both the notion of hyper generalized recurrent manifolds [A.A. Shaikh and A. Patra, On a generalized class of recurrent manifolds, Arch. Math. (Brno) 46 (2010) 71--78.] and weakly generalized recurrent manifolds [A.A. Shaikh and I. Roy, On weakly generalized recurrent manifolds, Ann. Univ. Sci. Budapest Rolando Eotvos, Sect. Math. 54 (2011) 35--45.]. The nature of associated 1-forms of a super generalized recurrent manifold is determined and it is proved that on a Roter type manifold [R. Deszcz, On Roter type manifolds, in: 5th Conference on Geometry and Topology of Manifolds, Krynica, Poland, 2003.] such a notion is equivalent to the notion of generalized Ricci-recurrent manifold [U.C. De, N. Guha and D. Kamilya, On generalized Ricci-recurrent manifolds, Tensor (N.S.) 56 (1995), no. 3, 312--317.]. We also obtain a sufficient condition for a super generalized recurrent manifold to be a semisymmetric one and the existence of such notion is ensured by a proper example.
Recurrent manifold
hyper generalized recurrent manifold
weakly generalized recurrent manifold
super generalized recurrent manifold
semisymmetric manifold
Roter type manifold
2017
10
31
1209
1225
http://bims.iranjournals.ir/article_1017_221e80b605233294053c42a27b7694a7.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
A study on dimensions of modules
E.
Momtahan
M.
Motamedi
In this article we study relations between some algebraic operations such as tensor product and localization from one hand and some well-known dimensions such as uniform dimension, hollow dimension and type dimension from the other hand. Some minor applications to the ring $C(X)$ are observed.
Type dimension
uniform dimension
hollow dimension
2017
10
31
1227
1235
http://bims.iranjournals.ir/article_1019_5f3eeaeee7edcd5ce4f9941b12e161be.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
On pm$^+$ and finite character bi-amalgamation
M.
Tamekkante
E.M.
Bouba
Let $f:Arightarrow B$ 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 $Btimes C$ given by $Abowtie^{f,g}(J,J^{'})={(f(a)+j,g(a)+j^{'})/ a in A, (j,j^{'}) in Jtimes J^{'}}.$ In this paper, we study the transference of $pm^{+}$, $pm$ and finite character ring-properties in the bi-amalgamation.
Bi-amalgamated algebras
$pm^{+}$ rings
$pm$ rings
rings with finite character
2017
10
31
1237
1244
http://bims.iranjournals.ir/article_1018_d12be38a73db01fc326f798b6d1826c2.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Efficient quadrature rules for a class of cordial Volterra integral equations: A comparative study
H.
Majidian
A natural algorithm with an optimal order of convergence is proposed for numerical solution of a class of cordial weakly singular Volterra integral equations. The equations of this class appear in heat conduction problems with mixed boundary conditions. The algorithm is based on a representation of the solution and compound Gaussian quadrature rules with graded meshes. A comparative study is carried out, which points out that the proposed method is the most efficient one among other existing methods. In fact, the results of this paper introduce a most-efficient decisive-choice for computing the solution of the heat conduction model.
Cordial Volterra integral equation
heat conduction problem
mixed-type boundary condition
compound quadrature rule
graded mesh
2017
10
01
1245
1258
http://bims.iranjournals.ir/article_1020_80bdca2e204bb2940daa2f96c43eead0.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
On certain maximality principles
R.
Mohammadpour
We present streamlined proofs of certain maximality principles studied by Hamkins and Woodin. Moreover, we formulate an intermediate maximality principle, which is shown here to be equiconsistent with the existence of a weakly compact cardinal $kappa$ such that $V_{kappa}prec V$.
Hamkins' maximality principle
weakly compact cardinal
consistency result
2017
10
31
1259
1264
http://bims.iranjournals.ir/article_1021_ccb01899ce6ea9b8d4051086de55709f.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Application of frames in Chebyshev and conjugate gradient methods
H.
Jamali
E.
Afroomand
Given a frame of a separable Hilbert space $H$, we present some iterative methods for solving an operator equation $Lu=f$, where $L$ is a bounded, invertible and symmetric operator on $H$. We present some algorithms based on the knowledge of frame bounds, Chebyshev method and conjugate gradient method, in order to give some approximated solutions to the problem. Then we investigate the convergence and optimality of them.
Hilbert spaces
dual space
frame
Chebyshev polynomials
iterative method
2017
10
31
1265
1279
http://bims.iranjournals.ir/article_1023_0cb1da24283448175d3dd2f38ccde208.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Further inequalities for operator space numerical radius on 2*2 operator matrices
M.
Sattari
We present some inequalities for operator space numerical radius of $2times 2$ 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.
Operator space
numerical radius operator space
operator space numerical radius
block matrix
2017
10
31
1281
1285
http://bims.iranjournals.ir/article_1022_38e5e771e877dc0dd08cba8c789de388.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Stochastic evolution equations with multiplicative Poisson noise and monotone nonlinearity
E.
Salavati
B.Z.
Zangeneh
Semilinear stochastic evolution equations with multiplicative Poisson noise and monotone nonlinear drift in Hilbert spaces are considered. The coefficients are assumed to have linear growth. We do not impose coercivity conditions on coefficients. A novel method of proof for establishing existence and uniqueness of the mild solution is proposed. Examples on stochastic partial differential equations and stochastic delay differential equations are provided to demonstrate the theory developed.
Stochastic evolution equation
monotone operator
Levy noise
Ito type inequality
stochastic convolution integral
2017
10
01
1287
1299
http://bims.iranjournals.ir/article_1024_cca52c80d3906210deab1b1cc3480592.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Improvements of Young inequality using the Kantorovich constant
M.
Khosravi
A.
Sheikh Hosseini
Some improvements of Young inequality and its reverse for positive numbers with Kantorovich constant $K(t, 2)=frac{(1+t)^2}{4t}$ are given. Using these inequalities some operator inequalities and Hilbert-Schmidt norm versions for matrices are proved. In particular, it is shown that if $a, b$ are positive numbers and $0 leqslant nu leqslant 1,$ then for all integers $ kgeqslant 1: $ $K(h^{frac{1}{2^n}},2)^{r_n} asharp_{nu}b leqslant anabla_{nu} b - sum_{k=0}^{n-1}r_{k}left((a sharp_{frac{m_k}{2^k}} b )^{frac{1}{2}}- (a sharp_{frac{m_k+1}{2^k}}b )^{frac{1}{2}}right)^{2}leqslant K(h^{frac{1}{2^n}},2)^{R_n} asharp_{nu}b,$ where $m_k= [ 2^knu ] $ is the largest integer not greater than $2^knu$, $ r_0=min { nu, 1-nu}, $ $ _{k}=min { 2r_{k-1}, 1-2r_{k-1} } $ and $R_k=1-r_k$.
Heinz mean
Hilbert-Schmidt norm
Kantorovich constant
Young inequality
2017
10
31
1301
1311
http://bims.iranjournals.ir/article_1025_461e366823aee2c9e7465c996b81443d.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Dilations for $C^ast$-dynamical systems with abelian groups on Hilbert $C^ast$-modules
Z.
Wang
J.
Zhang
In this paper we investigate the dilations of completely positive definite representations of (C^ast)-dynamical systems with abelian groups on Hilbert (C^ast)-modules. We show that if ((mathcal{A}, G,alpha)) is a (C^ast)-dynamical system with (G) an abelian group, then every completely positive definite covariant representation ((pi,varphi,E)) of ((mathcal{A}, G,alpha)) on a Hilbert (C^ast)-module (E) admits an unitary dilation $((hat{pi},hat{varphi},hat{E})).$
Dilation
covariant representation
$C^ast$-dynamical system
Hilbert $C^ast$-module
2017
10
31
1313
1321
http://bims.iranjournals.ir/article_1026_7331f04fa6ff4e9f75048878a153860b.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Some topologies on the space of quasi-multipliers
M.
Adib
Assume that $A$ is a Banach algebra. We define the $beta-$topology and the $gamma-$topology on the space $QM_{el}(A^{*})$ of all bounded extended left quasi-multipliers of $A^{*}.$ We establish further properties of $(QM_{el}(A^{*}),gamma)$ when $A$ is a $C^{*}-$algebra. In particular, we characterize the $gamma-$dual of $QM_{el}(A^{*})$ and prove that $(QM_{el}(A^{*}),gamma)^{*},$ under the topology of bounded convergence, is isomorphic to $A^{***}.$
Quasi-multiplier
multiplier
Banach algebra
Arens regularity
strict topology
2017
10
31
1323
1332
http://bims.iranjournals.ir/article_1027_45df925b9641b847aae53438ef84a853.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Strongly nil-clean corner rings
P.
Danchev
We show that if $R$ is a ring with an arbitrary idempotent $e$ such that $eRe$ and $(1-e)R(1-e)$ are both strongly nil-clean rings, then $R/J(R)$ is nil-clean. In particular, under certain additional circumstances, $R$ is also nil-clean. These results somewhat improves on achievements due to Diesl in J. Algebra (2013) and to Koc{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 $ntimes n$ matrix ring $mathbb{M}_n(R)$ is nil-clean.
Nil-clean rings
strongly nil-clean rings
idempotents
nilpotents
Jacobson radical
2017
10
31
1333
1339
http://bims.iranjournals.ir/article_1028_dd5007f3d112d2a8f52ea8300cd6810b.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Inverse Sturm--Liouville problems using three spectra with finite number of transmissions and parameter dependent conditions
M.
Shahriari
In this manuscript, we study various by uniqueness results for inverse spectral problems of Sturm--Liouville operators using three spectrum with a finite number of discontinuities at interior points which we impose the usual transmission conditions. We consider both the cases of classical Robin and eigenparameter dependent boundary conditions.
Inverse Sturm--Liouville problem
eigenparameter dependent boundary conditions
internal discontinuities
three spectra
Weyl--Titchmarsh m-function
2017
10
31
1341
1355
http://bims.iranjournals.ir/article_1029_93aa5b089d89ac3bbdaa647733a67c7e.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Convergence of the sinc method applied to delay Volterra integral equations
L.
Shiri
M.
Zarebnia
In this paper, the numerical solutions of linear and nonlinear Volterra integral equations with nonvanishing delay are considered by two methods. The methods are developed by means of the sinc approximation with the single exponential (SE) and double exponential (DE) transformations. The existence and uniqueness of sinc-collocation solutions for these equations are provided. These methods improve conventional results and achieve exponential convergence. Numerical results are included to confirm the efficiency and accuracy of the methods.
Volterra integral equations
nonvanishing delay
sinc-collocation
2017
10
31
1357
1375
http://bims.iranjournals.ir/article_1030_327268c4a1a76cc464033904300485c4.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
A stochastic version analysis of an M/G/1 retrial queue with Bernoulli schedule
M.
Boualem
M.
Cherfaoui
N.
Djellab
D.
Aissani
In this work, we derive insensitive bounds for various performance measures of a single-server retrial queue with generally distributed inter-retrial times and Bernoulli schedule, under the special assumption that only the customer at the head of the orbit queue (i.e., a FCFS discipline governing the flow from the orbit to the server) is allowed to occupy the server. The methodology is strongly based on stochastic comparison techniques. Instead of studying a performance measure in a quantitative fashion, this approach attempts to reveal the relationship between the performance measures and the parameters of the system. We prove the monotonicity of the transition operator of the embedded Markov chain relative to strong stochastic ordering and increasing convex ordering. We obtain comparability conditions for the distribution of the number of customers in the system. Bounds are derived for the stationary distribution and some simple bounds for the mean characteristics of the system. The proofs of these results are based on the validation of some inequalities for some cumulative probabilities associated with every state $(m, n)$ of the system. Finally, the effects of various parameters on the performance of the system have been examined numerically.
Retrial queues
performance measures
stochastic orders
monotonicity
simulation
2017
10
31
1377
1397
http://bims.iranjournals.ir/article_1031_36e5f4fe5a81d41164abffb156f27b4b.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
An algorithm for approximating nondominated points of convex multiobjective optimization problems
M.
Ghaznavi
Z.
Azizi
In this paper, we present an algorithm for generating approximate nondominated points of a multiobjective optimization problem (MOP), where the constraints and the objective functions are convex. We provide outer and inner approximations of nondominated points and prove that inner approximations provide a set of approximate weakly nondominated points. The proposed algorithm can be applied for differentiable or nondifferentiable convex MOPs. To illustrate efficiency of the proposed algorithm for convex MOPs, we provide numerical examples.
Multiobjective optimization
convexity
nondominated point
efficient solution
approximation algorithm
differentiable problem
2017
10
31
1399
1415
http://bims.iranjournals.ir/article_1032_8a34f64f24ba1df7f512341ae057ca36.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Complete pivoting strategy for the $IUL$ preconditioner obtained from Backward Factored APproximate INVerse process
A.
Rafiei
M.
Bollhoefer
In this paper, we use a complete pivoting strategy to compute the IUL preconditioner obtained as the by-product of the Backward Factored APproximate INVerse process. This pivoting is based on the complete pivoting strategy of the Backward IJK version of Gaussian Elimination process. There is a parameter $alpha$ to control the complete pivoting process. We have studied the effect of different values of $alpha$ on the quality of the IUL preconditioner. For the numerical experiments section, the IUL factorization which is coupled with the complete pivoting is compared to the ILUTP and to the left-looking version of RIF which is coupled with the complete pivoting strategy. As the preprocessing, we have applied the maximum weighted matching coupled the Reverse Cuthill-Mckee (RCM) and multilevel nested dissection reordering.
Backward factored APproximate INVerse
IUL preconditioner
backward IJK version of Gaussian elimination
complete pivoting
ILUTP
left-looking RIF with pivoting
2017
10
31
1417
1456
http://bims.iranjournals.ir/article_1033_a0a902a62988d3118f5b4b4d8b35504d.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Very cleanness of generalized matrices
Y.
Kurtulmaz
An element $a$ in a ring $R$ is very clean in case there exists an idempotent $ein R$ 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 $ein R$ such that $ae = ea$ and either $a-ein J(R)$ or $a + ein J(R)$. Let $R$ be a local ring, and let $sin C(R)$. We prove that $Ain K_s(R)$ is very clean if and only if $Ain U(K_s(R))$, $Ipm Ain U(K_s(R))$ or $Ain K_s(R)$ is very J-clean.
Local ring
very clean ring
very $J$-clean ring
2017
10
31
1457
1465
http://bims.iranjournals.ir/article_1041_38bce449953dafb7205f4ec6885c5a9c.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Five-value rich lines, Borel directions and uniqueness of meromorphic functions
J.R.
Long
For a meromorphic function $f$ in the complex plane, we shall introduce the definition of five-value rich line of $f$, and study the uniqueness of meromorphic functions of finite order in an angular domain by involving the five-value rich line and Borel directions. Finally, the relationship between a five-value rich line and a Borel direction is discussed, that is, every Borel direction of $f$ is its five-value rich line, and the inverse statement holds when $f$ is of infinite order.
Borel direction
five-value rich line
meromorphic function
sharing value
uniqueness
2017
10
31
1467
1478
http://bims.iranjournals.ir/article_1055_2eadf39317ec9297f6148fc720caf2ce.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Some rank equalities for finitely many tripotent matrices
T.
Petik
H.
Ozdemir
A rank equality is established for the sum of finitely many tripotent matrices via elementary block matrix operations. Moreover, by using this equality and Theorems 8 and 10 in [Chen M. and et al. On the open problem related to rank equalities for the sum of finitely many idempotent matrices and its applications, The Scientific World Journal 2014 (2014), Article ID 702413, 7 pages.], some other rank equalities for tripotent matrices are given. Furthermore, we obtain several rank equalities related to some special types of matrices, some of which are available in the literature, from the results established.
Rank
elementary block matrix operations
idempotent matrix
tripotent matrix
2017
10
31
1479
1493
http://bims.iranjournals.ir/article_1037_3ff83cd867821e50f12900bc578fc89c.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Convex combinations of harmonic shears of slit mappings
L.
Shi
Z.-G.
Wang
A.
Rasila
Y.
Sun
In this paper, we study the convex combinations of harmonic mappings obtained by shearing a class of slit conformal mappings. Sufficient conditions for the convex combinations of harmonic mappings of this family to be univalent and convex in the horizontal direction are derived. Several examples of univalent harmonic mappings constructed by using these methods are presented to illustrate potential applications of the main results.
Harmonic mapping
slit mapping
convex combination
shear construction
2017
10
31
1495
1510
http://bims.iranjournals.ir/article_1046_c2564c5c47e770c3777a5cef16455c1e.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
On a p-Laplacian system and a generalization of the Landesman-Lazer type condition
B.Q.
Hung
H.Q.
Toan
This article shows the existence of weak solutions of a resonance problem for nonuniformly p-Laplacian system in a bounded domain in $mathbb{R}^N$. Our arguments are based on the minimum principle and rely on a generalization of the Landesman-Lazer type condition.
Semilinear elliptic equation
non-uniform
Landesman-Lazer condition
minimum principle
2017
10
31
1511
1528
http://bims.iranjournals.ir/article_1036_a46a25c9bc4119887a0c69ea7fab5737.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
A simple proof of Zariski's Lemma
A.
Azarang
Our aim in this very short note is to show that the proof of the following well-known fundamental lemma of Zariski follows from an argument similar to the proof of the fact that the rational field $mathbb{Q}$ is not a finitely generated $mathbb{Z}$-algebra.
Zariski's Lemma
PID
Field
2017
10
31
1529
1530
http://bims.iranjournals.ir/article_1047_f803ea9ce410ca4863df36ec64d40f32.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
NSE characterization of some linear groups
N.
Ahanjideh
L.
Mousavi
B.
Taeri
For a finite group $G$, let $nse(G)={m_kmid kinpi_e(G)}$, 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 $Gcong L_m(2)$ if and only if $pmid |G|$ and $nse(G)=nse(L_m(2))$, where $min {n,n+1}$ and $2^n-1=p$ is a prime number.
Set of the numbers of elements of the same order
prime graph
Mersenne number
2017
10
31
1531
1542
http://bims.iranjournals.ir/article_1058_2c5b6c17ba5cdd918988ed6c7b89c0df.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2017
43
5
Measure of non strict singularity of Schechter essential spectrum of two bounded operators and application
F.
Abdmouleh
I.
Walha
In this paper, we discuss the essential spectrum of sum of two bounded operators using measure of non strict singularity. Based on this new investigation, a problem of one-speed neutron transport operator is presented.
Fredholm operators
lower (respectively upper) semi-Fredholm operators
essential spectrum
measure of non-strict-singularity
one-speed neutron transport operator
2017
10
01
1543
1558
http://bims.iranjournals.ir/article_1050_50a956cc722e6b159778d8af6ea79cff.pdf