2018-07-23T20:14:43Z
http://bims.iranjournals.ir/?_action=export&rf=summon&issue=86
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Bulletin of the Iranian Mathematical Society
2016
11
01
http://bims.iranjournals.ir/article_861_accfc01f02b7e1ec0a15b183341aeac2.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Forced oscillations of a damped Korteweg-de Vries equation on a periodic domain
M.
Chen
In this paper, we investigate a damped Korteweg-de Vries equation with forcing on a periodic domain $mathbb{T}=mathbb{R}/(2pimathbb{Z})$. We can obtain that if the forcing is periodic with small amplitude, then the solution becomes eventually time-periodic.
Forced oscillation
Korteweg-de Vries equation
stability
time-periodic solution
2016
11
01
1027
1038
http://bims.iranjournals.ir/article_862_ab038992016b1b175d32df688062e53c.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Boundary temperature reconstruction in an inverse heat conduction problem using boundary integral equation method
M.
Garshasbi
F.
Hassani
In this paper, we consider an inverse boundary value problem for two-dimensional heat equation in an annular domain. This problem consists of determining the temperature on the interior boundary curve from the Cauchy data (boundary temperature and heat flux) on the exterior boundary curve. To this end, the boundary integral equation method is used. Since the resulting system of linear algebraic equations is ill-posed, the Tikhonov first-order regularization procedure is employed to obtain a stable solution. Determination of regularization parameter is based on L-curve technique. Some numerical examples for the feasibility of the proposed method are presented.
Inverse boundary problem
heat equation
boundary integral equation method
regularization.
2016
11
01
1039
1057
http://bims.iranjournals.ir/article_863_d469ccbf86a94e4c4831982ef32f13b6.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
On a generalization of condition (PWP)
X.
Liang
Y.
Luo
There is a flatness property of acts over monoids called Condition $(PWP)$ which, so far, has received much attention. In this paper, we introduce Condition GP-$(P)$, which is a generalization of Condition $(PWP)$. Firstly, some characterizations of monoids by Condition GP-$(P)$ of their (cyclic, Rees factor) acts are given, and many known results are generalized. Moreover, some possible conditions on monoids that describe when their diagonal acts satisfy Condition GP-$(P)$ are found. Finally, using some new types of epimorphisms, an alternative description of Condition GP-$(P)$ (resp., Condition $(PWP)$) is obtained, and directed colimits of these new epimorphisms are investigated.
$S$-act
Condition $(PWP)$
condition GP-$(P)$
generally left right ideal
quasi G-2-pure epimorphism
2016
11
01
1057
1076
http://bims.iranjournals.ir/article_864_6aca97cc012989be8545639bb27655ed.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Approximate solution of dual integral equations
S.
Ahdiaghdam
K.
Ivaz
S.
Shahmorad
We study dual integral equations which appear in formulation of the potential distribution of an electrified plate with mixed boundary conditions. These equations will be converted to a system of singular integral equations with Cauchy type kernels. Using Chebyshev polynomials, we propose a method to approximate the solution of Cauchy type singular integral equation which will be used to approximate the solution of the main dual integral equations. Numerical results demonstrate effectiveness of this method.
Dual integral equation
Cauchy type integral equation
Fourier transform
2016
11
01
1077
1086
http://bims.iranjournals.ir/article_865_36fdbd67705679576cbc4c02707cf62d.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
On the bounds in Poisson approximation for independent geometric distributed random variables
T. L.
Hung
L. T.
Giang
The main purpose of this note is to establish some bounds in Poisson approximation for row-wise arrays of independent geometric distributed random variables using the operator method. Some results related to random sums of independent geometric distributed random variables are also investigated.
Poisson approximation
linear operator
geometric random variable
random sums
2016
11
01
1087
1096
http://bims.iranjournals.ir/article_866_5fccc709565917424a38a1fa4d5c23c3.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Which elements of a finite group are non-vanishing?
M.
Arezoomand
B.
Taeri
Let $G$ be a finite group. An element $gin G$ is called non-vanishing, if for every irreducible complex character $chi$ of $G$, $chi(g)neq 0$. The bi-Cayley graph ${rm BCay}(G,T)$ of $G$ with respect to a subset $Tsubseteq G$, is an undirected graph with vertex set $Gtimes{1,2}$ and edge set ${{(x,1),(tx,2)}mid xin G, tin T}$. Let ${rm nv}(G)$ be the set of all non-vanishing elements of a finite group $G$. We show that $gin nv(G)$ if and only if the adjacency matrix of ${rm BCay}(G,T)$, where $T={rm Cl}(g)$ is the conjugacy class of $g$, is non-singular. We prove that if the commutator subgroup of $G$ has prime order $p$, then (1) $gin {rm nv}(G)$ if and only if $|Cl(g)|
Non-vanishing element
character
conjugacy class
Bi-Cayley graph
2016
11
01
1097
1106
http://bims.iranjournals.ir/article_867_e6b164bbe3a5bd8febacd1a5524efcc6.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Numerical approach for solving a class of nonlinear fractional differential equation
S.
Irandoust-pakchin
M.
Lakestani
H.
Kheiri
It is commonly accepted that fractional differential equations play an important role in the explanation of many physical phenomena. For this reason we need a reliable and efficient technique for the solution of fractional differential equations. This paper deals with the numerical solution of a class of fractional differential equation. The fractional derivatives are described based on the Caputo sense. Our main aim is to generalize the Chebyshev cardinal operational matrix to the fractional calculus. In this work, the Chebyshev cardinal functions together with the Chebyshev cardinal operational matrix of fractional derivatives are used for numerical solution of a class of fractional differential equations. The main advantage of this approach is that it reduces fractional problems to a system of algebraic equations. The method is applied to solve nonlinear fractional differential equations. Illustrative examples are included to demonstrate the validity and applicability of the presented technique.
Fractional-order differential equation
operational matrix of fractional derivative
Caputo derivative
Chebyshev cardinal function
collocation method
2016
11
01
1107
1126
http://bims.iranjournals.ir/article_868_26827a7d21fe2b110ccd0dc9c647f92a.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
The use of inverse quadratic radial basis functions for the solution of an inverse heat problem
F.
Parzlivand
A.
Shahrezaee
In this paper, a numerical procedure for an inverse problem of simultaneously determining an unknown coefficient in a semilinear parabolic equation subject to the specification of the solution at an internal point along with the usual initial boundary conditions is considered. The method consists of expanding the required approximate solution as the elements of the inverse quadratic radial basis functions (IQ-RBFs). The operational matrix of derivative for IQ-RBFs is introduced and the new computational technique is used for this purpose. The operational matrix of derivative is utilized to reduce the problem to a set of algebraic equations. Some examples are given to demonstrate the validity and applicability of the new method and a comparison is made with the existing results.
Collocation
inverse parabolic problem
scattered data
RBFs
2016
11
01
1127
1142
http://bims.iranjournals.ir/article_869_56874af181e3b46e92db683c4c49a920.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Composition operators and natural metrics in meromorphic function classes $Q_p$
A.
Kamal
In this paper, we investigate some results on natural metrics on the $mu$-normal functions and meromorphic $Q_p$-classes. Also, these classes are shown to be complete metric spaces with respect to the corresponding metrics. Moreover, compact composition operators $C_phi$ and Lipschitz continuous operators acting from $mu$-normal functions to the meromorphic $Q_p$-classes are characterized by conditions depending only on $phi.$
Meromorphic classes
composition operators
Lipschitz continuous
2016
11
01
1143
1154
http://bims.iranjournals.ir/article_870_35e24f164aba15e6073c999fba0d70b5.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Multiplication operators on Banach modules over spectrally separable algebras
J.
Bračič
Let $mathcal{A}$ be a commutative Banach algebra and $mathscr{X}$ be a left Banach $mathcal{A}$-module. We study the set ${rm Dec}_{mathcal{A}}(mathscr{X})$ of all elements in $mathcal{A}$ which induce a decomposable multiplication operator on $mathscr{X}$. In the case $mathscr{X}=mathcal{A}$, ${rm Dec}_{mathcal{A}}(mathcal{A})$ is the well-known Apostol algebra of $mathcal{A}$. We show that ${rm Dec}_{mathcal{A}}(mathscr{X})$ is intimately related with the largest spectrally separable subalgebra of $mathcal{A}$ and in this context we give some results which are related to an open question if Apostol algebra is regular for any commutative algebra $mathcal{A}$.
Commutative Banach algebra
decomposable multiplication operator
spectrally separable algebra
2016
11
01
1155
1167
http://bims.iranjournals.ir/article_871_9f5eadc32836600803a25c1fd5936d46.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
On a functional equation for symmetric linear operators on $C^{*}$ algebras
A.
Taghavi
Let $A$ be a $C^{*}$ algebra, $T: Arightarrow A$ be a linear map which satisfies the functional equation $T(x)T(y)=T^{2}(xy),;;T(x^{*})=T(x)^{*} $. We prove that under each of the following conditions, $T$ must be the trivial map $T(x)=lambda x$ for some $lambda in mathbb{R}$: i) $A$ is a simple $C^{*}$-algebra. ii) $A$ is unital with trivial center and has a faithful trace such that each zero-trace element lies in the closure of the span of commutator elements. iii) $A=B(H)$ where $H$ is a separable Hilbert space. For a given field $F$, we consider a similar functional equation {$ T(x)T(y) =T^{2}(xy), T(x^{tr})=T(x)^{tr}, $} where $T$ is a linear map on $M_{n}(F)$ and "tr" is the transpose operator. We prove that this functional equation has trivial solution for all $nin mathbb{N}$ if and only if $F$ is a formally real field.
"Functional Equations"
"$C^{*}$ algebras"
" Formally real fields"
2016
11
01
1169
1177
http://bims.iranjournals.ir/article_872_fd7287eb7f1365d9156e9da3ccb25196.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
The Fischer-Clifford matrices and character table of the maximal subgroup $2^9{:}(L_3(4){:}S_3)$ of $U_6(2){:}S_3$
A. L.
Prins
The full automorphism group of $U_6(2)$ is a group of the form $U_6(2){:}S_3$. The group $U_6(2){:}S_3$ has a maximal subgroup $2^9{:}(L_3(4){:}S_3)$ of order 61931520. In the present paper, we determine the Fischer-Clifford matrices (which are not known yet) and hence compute the character table of the split extension $2^9{:}(L_3(4){:}S_3)$.
Coset analysis
Fischer-Clifford matrices
permutation character
fusion map
2016
10
01
1179
1195
http://bims.iranjournals.ir/article_873_6ec8116653a7fc6145c53dd9e3228b5f.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Some commutativity theorems for $*$-prime rings with $(sigma,tau)$-derivation
M.
Ashraf
N.
Parveen
Let $R$ be a $*$-prime ring with center $Z(R)$, $d$ a non-zero $(sigma,tau)$-derivation of $R$ with associated automorphisms $sigma$ and $tau$ of $R$, such that $sigma$, $tau$ and $d$ commute with $'*'$. Suppose that $U$ is an ideal of $R$ such that $U^*=U$, and $C_{sigma,tau}={cin R~|~csigma(x)=tau(x)c~mbox{for~all}~xin R}.$ In the present paper, it is shown that if characteristic of $R$ is different from two and $[d(U),d(U)]_{sigma,tau}={0},$ then $R$ is commutative. Commutativity of $R$ has also been established in case if $[d(R),d(R)]_{sigma,tau}subseteq C_{sigma,tau}.$
Prime-rings
derivations
ideal
involution map
2016
11
01
1197
1206
http://bims.iranjournals.ir/article_874_0ec3eca69c4da52c1cf3357568f2b7fd.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Common solutions to pseudomonotone equilibrium problems
D. V.
Hieu
In this paper, we propose two iterative methods for finding a common solution of a finite family of equilibrium problems for pseudomonotone bifunctions. The first is a parallel hybrid extragradient-cutting algorithm which is extended from the previously known one for variational inequalities to equilibrium problems. The second is a new cyclic hybrid extragradient-cutting algorithm. In the cyclic algorithm, using the known techniques, we can perform and develop practical numerical experiments.
Hybrid method
parallel algorithm
cyclic algorithm
extragradient method
equilibrium problem
2016
10
01
1207
1219
http://bims.iranjournals.ir/article_875_e39c67b7360a9dceda155977e3771762.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
$mathcal{X}$-injective and $mathcal{X}$-projective complexes
T.
Özen
E.
Yıldırım
Let $mathcal{X}$ be a class of $R$-modules. In this paper, we investigate ;$mathcal{X}$-injective (projective) and DG-$mathcal{X}$-injective (projective) complexes which are generalizations of injective (projective) and DG-injective (projective) complexes. We prove that some known results can be extended to the class of ;$mathcal{X}$-injective (projective) and DG-$mathcal{X}$-injective (projective) complexes for this general settings.
Injective (Projective) complex
precover
preenvelope
2016
10
01
1221
1235
http://bims.iranjournals.ir/article_876_bcc953321d1ed4f3a9c517d160fe4c40.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Sufficient global optimality conditions for general mixed integer nonlinear programming problems
J.
Quan
Z. Y.
Wu
G. Q.
Li
In this paper, some KKT type sufficient global optimality conditions for general mixed integer nonlinear programming problems with equality and inequality constraints (MINPP) are established. We achieve this by employing a Lagrange function for MINPP. In addition, verifiable sufficient global optimality conditions for general mixed integer quadratic programming problems are derived easily. Numerical examples are also presented.
Sufficient global optimality conditions
mixed integer nonlinear programming
mixed integer quadratic programming
2016
10
01
1237
1246
http://bims.iranjournals.ir/article_877_e02f8f1f336deb5527f980f598eefbff.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
A note on Fouquet-Vanherpe’s question and Fulkerson conjecture
F.
Chen
The excessive index of a bridgeless cubic graph $G$ is the least integer $k$, such that $G$ can be covered by $k$ perfect matchings. An equivalent form of Fulkerson conjecture (due to Berge) is that every bridgeless cubic graph has excessive index at most five. Clearly, Petersen graph is a cyclically 4-edge-connected snark with excessive index at least 5, so Fouquet and Vanherpe asked whether Petersen graph is the only one with that property. H"{a}gglund gave a negative answer to their question by constructing two graphs Blowup$(K_4, C)$ and Blowup$(Prism, C_4)$. Based on the first graph, Esperet et al. constructed infinite families of cyclically 4-edge-connected snarks with excessive index at least five. Based on these two graphs, we construct infinite families of cyclically 4-edge-connected snarks $E_{0,1,2,ldots, (k-1)}$ in which $E_{0,1,2}$ is Esperet et al.'s construction. In this note, we prove that $E_{0,1,2,3}$ has excessive index at least five, which gives a strongly negative answer to Fouquet and Vanherpe's question. As a subcase of Fulkerson conjecture, H"{a}ggkvist conjectured that every cubic hypohamiltonian graph has a Fulkerson-cover. Motivated by a related result due to Hou et al.'s, in this note we prove that Fulkerson conjecture holds on some families of bridgeless cubic graphs.
Fulkerson-cover
excessive index
snark
hypohamiltonian graph
2016
10
01
1247
1258
http://bims.iranjournals.ir/article_878_1c321310c71687bcfea04de293b6da0f.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Operator-valued tensors on manifolds
H.
Feizabadi
N.
Boroojerdian
In this paper we try to extend geometric concepts in the context of operator valued tensors. To this end, we aim to replace the field of scalars $ mathbb{R} $ by self-adjoint elements of a commutative $ C^star $-algebra, and reach an appropriate generalization of geometrical concepts on manifolds. First, we put forward the concept of operator-valued tensors and extend semi-Riemannian metrics to operator valued metrics. Then, in this new geometry, some essential concepts of Riemannian geometry such as curvature tensor, Levi-Civita connection, Hodge star operator, exterior derivative, divergence,... will be considered.
Operator-valued tensors
operator-valued semi-Riemannian metrics
Levi-Civita connection
curvature
Hodge star operator
2016
10
01
1259
1277
http://bims.iranjournals.ir/article_879_44f3202eefb900362bb1960d135193a5.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
Irreducible characters of Sylow $p$-subgroups of the Steinberg triality groups ${}^3D_4(p^{3m})$
T.
Le
Here we construct and count all ordinary irreducible characters of Sylow $p$-subgroups of the Steinberg triality groups ${}^3D_4(p^{3m})$.
Irreducible character
root system
Sylow subgroup
Steinberg triality
2016
10
01
1279
1291
http://bims.iranjournals.ir/article_880_35a9b44674a8153d0f083d3be4621a0b.pdf
Bulletin of the Iranian Mathematical Society
BIMS
1017-060X
1017-060X
2016
42
5
On list vertex 2-arboricity of toroidal graphs without cycles of specific length
H.
Zhang
The vertex arboricity $rho(G)$ of a graph $G$ is the minimum number of subsets into which the vertex set $V(G)$ can be partitioned so that each subset induces an acyclic graph. A graph $G$ is called list vertex $k$-arborable if for any set $L(v)$ of cardinality at least $k$ at each vertex $v$ of $G$, one can choose a color for each $v$ from its list $L(v)$ so that the subgraph induced by every color class is a forest. The smallest $k$ for a graph to be list vertex $k$-arborable is denoted by $rho_l(G)$. Borodin, Kostochka and Toft (Discrete Math. 214 (2000) 101-112) first introduced the list vertex arboricity of $G$. In this paper, we prove that $rho_l(G)leq 2$ for any toroidal graph without 5-cycles. We also show that $rho_l(G)leq 2$ if $G$ contains neither adjacent 3-cycles nor cycles of lengths 6 and 7.
Vertex arboricity
toroidal graph
structure
cycle
2016
10
01
1293
1303
http://bims.iranjournals.ir/article_881_1c2751a2e851f892b91c1fd5de3e21f4.pdf