Bulletin of the Iranian Mathematical Society
text
article
2016
eng
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
http://bims.iranjournals.ir/article_892_76367872db19dee6e35769d297c7cbaf.pdf
Image processing by alternate dual Gabor frames
A.
Arefijammal
Department of Mathematics and Computer Sciences, Hakim Sabzevari University, Sabzevar, Iran.
author
E.
Zekaee
Department of Mathematics, Shahrood University of
Technology, Shahrood, Iran.
author
text
article
2016
eng
We present an application of the dual Gabor frames to image processing. Our algorithm is based on finding some dual Gabor frame generators which reconstructs accurately the elements of the underlying Hilbert space. The advantages of these duals constructed by a polynomial of Gabor frame generators are compared with their canonical dual.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1305
1314
http://bims.iranjournals.ir/article_893_b5c916fea6f1c621cd65bf56bfe40a17.pdf
A remark on the means of the number of divisors
M.
Hassani
Department of Mathematics, University of Zanjan, University Blvd., 45371-38791, Zanjan, Iran.
author
text
article
2016
eng
We obtain the asymptotic expansion of the sequence with general term $\frac{A_n}{G_n}$, where $A_n$ and $G_n$ are the arithmetic and geometric means of the numbers $\d(1),\d(2),\dots,\d(n)$, with $\d(n)$ denoting the number of positive divisors of $n$. Also, we obtain some explicit bounds concerning $G_n$ and $\frac{A_n}{G_n}$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1315
1330
http://bims.iranjournals.ir/article_894_9034a853545c34bb0518d238b490e090.pdf
Co-centralizing generalized derivations acting on multilinear polynomials in prime rings
B.
Dhara
Department of Mathematics, Belda College, Belda, Paschim Medinipur, 721424, W.B., India.
author
S.
Kar
Department of Mathematics, Jadavpur University, Kolkata-700032, W.B., India.
author
K. G.
Pradhan
{Department of Mathematics, Belda College, Belda, Paschim Medinipur, 721424, W.B., India.
author
text
article
2016
eng
Let $R$ be a noncommutative prime ring of characteristic different from $2$, $U$ the Utumi quotient ring of $R$, $C$ $(=Z(U))$ the extended centroid of $R$. Let $0\neq a\in R$ and $f(x_1,\ldots,x_n)$ a multilinear polynomial over $C$ which is noncentral valued on $R$. Suppose that $G$ and $H$ are two nonzero generalized derivations of $R$ such that $a(H(f(x))f(x)-f(x)G(f(x)))\in C$ for all $x=(x_1,\ldots,x_n)\in R^n$. one of the following holds: $f(x_1,\ldots,x_n)^2$ is central valued on $R$ and there exist $b,p,q\in U$ such that $H(x)=px+xb$ for all $x\in R$, $G(x)=bx+xq$ for all $x\in R$ with $a(p-q)\in C$; there exist $p,q\in U$ such that $H(x)=px+xq$ for all $x\in R$, $G(x)=qx$ for all $x\in R$ with $ap=0$; $f(x_1,\ldots,x_n)^2$ is central valued on $R$ and there exist $q\in U$, $\lambda\in C$ and an outer derivation $g$ of $U$ such that $H(x)=xq+\lambda x-g(x)$ for all $x\in R$, $G(x)=qx+g(x)$ for all $x\in R$, with $a\in C$; $R$ satisfies $s_4$ and there exist $b,p\in U$ such that $H(x)=px+xb$ for all $x\in R$, $G(x)=bx+xp$ for all $x\in R$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1331
1342
http://bims.iranjournals.ir/article_895_8c03085c5ab1d35e79d83f6495139262.pdf
On natural homomorphisms of local cohomology modules
W.
Mahmood
Quaid-i-Azam University, Islamabad-Pakistan.
author
text
article
2016
eng
Let $M$ be a non-zero finitely generated module over a commutative Noetherian local ring $(R,\mathfrak{m})$ with $\dim_R(M)=t$. Let $I$ be an ideal of $R$ with $grade(I,M)=c$. In this article we will investigate several natural homomorphisms of local cohomology modules. The main purpose of this article is to investigate when the natural homomorphisms $\gamma: Tor^{R}_c(k,H^c_I(M))\to k\otimes_R M$ and $\eta: Ext^{d}_R(k,H^c_I(M))\to Ext^{t}_R(k, M)$ are non-zero where $d:=t-c$. In fact for a Cohen-Macaulay module $M$ we will show that the homomorphism $\eta$ is injective (resp. surjective) if and only if the homomorphism $H^{d}_{\mathfrak{m}}(H^c_{I}(M))\to H^t_{\mathfrak{m}}(M)$ is injective (resp. surjective) under the additional assumption of vanishing of Ext modules. The similar results are obtained for the homomorphism $\gamma$. Moreover we will construct the natural homomorphism $Tor^{R}_c(k, H^c_I(M))\to Tor^{R}_c(k, H^c_J(M))$ for the ideals $J\subseteq I$ with $c = grade(I,M)= grade(J,M)$. There are several sufficient conditions on $I$ and $J$ to provide this homomorphism is an isomorphism.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1343
1361
http://bims.iranjournals.ir/article_896_f9aeadbc22b7c8b96538dded5e201ad6.pdf
Global convergence of an inexact interior-point method for convex quadratic symmetric cone programming
M.
Pirhaji
Department of Applied Mathematics, Faculty of Mathematical Sciences,
Shahrekord University, P.O. Box 115, Shahrekord, Iran.
author
H.
Mansouri
Department of Applied Mathematics, Faculty of Mathematical Sciences,
Shahrekord University, P.O. Box 115, Shahrekord, Iran.
author
M.
Zangiabadi
Department of Applied Mathematics, Faculty of Mathematical Sciences,
Shahrekord University, P.O. Box 115, Shahrekord, Iran.
author
text
article
2016
eng
In this paper, we propose a feasible interior-point method for convex quadratic programming over symmetric cones. The proposed algorithm relaxes the accuracy requirements in the solution of the Newton equation system, by using an inexact Newton direction. Furthermore, we obtain an acceptable level of error in the inexact algorithm on convex quadratic symmetric cone programming (CQSCP). We also prove that the iteration bound for the feasible short-step method is $O(\sqrt{n}\log\frac{1}{\varepsilon})$, and $O(n\log\frac{1}{\varepsilon})$ for the large-step method which coincide with the currently best known iteration bounds for CQSCPs.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1363
1385
http://bims.iranjournals.ir/article_897_bc55eece1cb0cab824b2d11aa4f3e3ec.pdf
Quasilinear Schrödinger equations involving critical exponents in $\mathbb{\textbf{R}}^2$
Y.
Wu
Department of Mathematics and Computer Science, Guizhou
Normal University, Guiyang, Guizhou, 550001, P. R. of China.
author
Y.
Yao
School of Mathematics, South China University of Technology, Guangzhou, Guangdong 510640, P. R. of China.
author
text
article
2016
eng
We study the existence of soliton solutions for a class of quasilinear elliptic equation in $\mathbb{\textbf{R}}^2$ with critical exponential growth. This model has been proposed in the self-channeling of a high-power ultra short laser in matter.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1387
1401
http://bims.iranjournals.ir/article_898_1e40b3dd419ecdd6d6aa9bdd508eb76b.pdf
Simple groups with the same prime graph as $D_n(q)$
B.
Khosravi
Department of Pure Mathematics, Faculty of Mathematics and Computer Sciences,
Amirkabir University of Technology, 424,
Hafez Ave., Tehran 15914, Iran.
author
A.
Babai
Department of Mathematics, University of Qom, P.O. Box 37185-3766, Qom, Iran.
author
text
article
2016
eng
Vasil'ev posed Problem 16.26 in [The Kourovka Notebook: Unsolved Problems in Group Theory, 16th ed.,Sobolev Inst. Math., Novosibirsk (2006).] as follows:Does there exist a positive integer $k$ such that there are no $k$ pairwise nonisomorphicnonabelian finite simple groups with the same graphs of primes? Conjecture: $k = 5$.In [Zvezdina, On nonabelian simple groups having the same prime graph as an alternating group, Siberian Math. J., 2013] the above conjecture is positively answered when one of these pairwise nonisomorphic groups is an alternating group.In this paper, we continue this work and determine all nonabelian simple groups, which have the same prime graph as the nonabelian simple group $D_n(q)$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1403
1427
http://bims.iranjournals.ir/article_899_fccfee9cd92567c1b231239ddc9bfa0f.pdf
Positive solutions of $n$th-order $m$-point boundary value problems
I.
Yaslan Karaca
Department of Mathematics, Ege University, Bornova, 35100 Izmir, Turkey.
author
F.
Tokmak Fen
Neuroscience Institute, Georgia State University, Atlanta, Georgia, 30303 USA; Department of Mathematics, Gazi University, Teknikokullar, 06500 Ankara, Turkey.
author
text
article
2016
eng
In this paper, by using four functionals fixed point theorem, we obtain sufficient conditions for the existence of at least one positive solution of an $n$th-order $m$-point boundary value problem. As an application, we give an example to demonstrate our main result.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1429
1439
http://bims.iranjournals.ir/article_900_67943c2d6f324d2bd9469252d67e06c0.pdf
On generalizations of semiperfect and perfect rings
Y.
Mehmet Demirci
Department of Mathematics, Sinop University, 57000, Sinop, Turkey.
author
text
article
2016
eng
We call a ring $R$ right generalized semiperfect if every simple right $R$-module is an epimorphic image of a flat right $R$-module with small kernel, that is, every simple right $R$-module has a flat $B$-cover. We give some properties of such rings along with examples. We introduce flat strong covers as flat covers which are also flat $B$-covers and give characterizations of $A$-perfect, $B$-perfect and perfect rings in terms of flat strong covers.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1441
1450
http://bims.iranjournals.ir/article_901_546323e6ae36551a0f01a84955ee0e0c.pdf
Existence and nonexistence of positive solution for sixth-order boundary value problems
H.
Mirzaei
Faculty of Basic Sciences, Sahand University of Technology, Tabriz, Iran.
author
text
article
2016
eng
In this paper, we formulate the sixth-order boundary value problem as Fredholm integral equation by finding Green's function and obtain the sufficient conditions for existence and multiplicity of positive solution for this problem. Also nonexistence results are obtained. An example is given to illustrate the results of paper.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1451
1458
http://bims.iranjournals.ir/article_902_2e9751112c0f6a8a0ad4c17431e11af8.pdf
Differential subordination and superordination results associated with the Wright function
Á.
Barciz
Department of Economics, Babes-Bolyai University, 400591 Cluj-Napoca, Romania
and
Institute of Applied Mathematics, 'Obuda University, 1034 Budapest, Hungary.
author
S.
Kant
Department of Mathematics, Government Dungar College, 334001 Bikaner, India.
author
J. K.
Prajapat
Department of Mathematics, Central University of Rajasthan, 305817 Kishangarh, Rajasthan, India.
author
text
article
2016
eng
An operator associated with the Wright function is introduced in the open unit disk. Differential subordination and superordination results associated with this operator are obtained by investigating appropriate classes of admissible functions. In particular, some inequalities for modified Bessel functions are also obtained.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1459
1477
http://bims.iranjournals.ir/article_903_a50f6bbefef6ab07f840f8681a9504de.pdf
On time-dependent neutral stochastic evolution equations with a fractional Brownian motion and infinite delays
Z.
Li
School of Information and Mathematics,
Yangtze University, Jingzhou 434023, China.
author
L.
Xu
School of Information and Mathematics,
Yangtze University, Jingzhou 434023, China.
author
X.
Li
School of Information and Mathematics,
Yangtze University, Jingzhou 434023, China and
School of Mathematical Sciences,
Beijing Normal University, Beijing 100875, China.
author
text
article
2016
eng
In this paper, we consider a class of time-dependent neutral stochastic evolution equations with the infinite delay and a fractional Brownian motion in a Hilbert space. We establish the existence and uniqueness of mild solutions for these equations under non-Lipschitz conditions with Lipschitz conditions being considered as a special case. An example is provided to illustrate the theory
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1479
1496
http://bims.iranjournals.ir/article_904_070920b9fa736281ee5571ed2c3f208f.pdf
Growth of meromorphic solutions for complex difference equations of Malmquist type
Y. Y.
Zhang
LMIB & School of Mathematics and Systems Science, Beihang University, Beijing, 100191, China.
author
Z. S.
Gao
LMIB & School of Mathematics and Systems Science, Beihang University, Beijing, 100191, China.
author
J. L.
Zhang
LMIB & School of Mathematics and Systems Science, Beihang University, Beijing, 100191, China.
author
text
article
2016
eng
In this paper, we give some necessary conditions for a complex difference equation of Malmquist type $$\sum^n_{j=1}f(z+c_j)=\frac{P(f(z))}{Q(f(z))},$$ where $n(\in{\mathbb{N}})\geq{2}$, and $P(f(z))$ and $Q(f(z))$ are relatively prime polynomials in $f(z)$ with small functions as coefficients, admitting a meromorphic function of finite order. Moreover, the properties of finite order transcendental meromorphic solutions for complex difference equation $\prod^n_{j=1}f(z+c_j)=P(f(z))/Q(f(z))$ are also investigated.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1497
1505
http://bims.iranjournals.ir/article_905_ea7deb684570bd139e25b0b9450c544c.pdf
Nonexistence and existence results for a 2$n$th-order $p$-Laplacian discrete Neumann boundary value problem
H.
Shi
Modern Business and Management
Department, Guangdong Construction Polytechnic, Guangzhou 510440, China.
author
X.
Liu
Oriental Science and
Technology College, Hunan Agricultural University, Changsha 410128, China, and Science College, Hunan
Agricultural University, Changsha 410128, China.
author
Y.
Zhang
Packaging Engineering Institute,
Jinan University, Zhuhai 519070, China.
author
text
article
2016
eng
This paper is concerned with a 2nth-order p-Laplacian difference equation. By using the critical point method, we establish various sets of sufficient conditions for the nonexistence and existence of solutions for Neumann boundary value problem and give some new results. Results obtained successfully generalize and complement the existing ones.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1507
1521
http://bims.iranjournals.ir/article_906_60912a337544b6e988cdbda95ec1ce44.pdf
A remark on Remainders of homogeneous spaces in some compactifications
H.
Wang
Department of Mathematics, Shandong Agricultural University, Taian 271018, China.
author
W.
He
School of Mathematics, Nanjing Normal University, Nanjing 210046, China.
author
text
article
2016
eng
We prove that a remainder $Y$ of a non-locally compact rectifiable space $X$ is locally a $p$-space if and only if either $X$ is a Lindel\"{o}f $p$-space or $X$ is $\sigma$-compact, which improves two results by Arhangel'skii. We also show that if a non-locally compact rectifiable space $X$ that is locally paracompact has a remainder $Y$ which has locally a $G_{\delta}$-diagonal, then both $X$ and $Y$ are separable and metrizable, which improves another Arhangel'skii's result. It is proved that if a non-locally compact paratopological group $G$ has a locally developable remainder $Y$, then either $G$ and $Y$ are separable and metrizable, or $G$ is a $\sigma$-compact space with a countable network, which improves a result by Wang-He.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1523
1534
http://bims.iranjournals.ir/article_907_6be825dad83aff4dcbc3678dc36a3833.pdf
Spacetimes admitting quasi-conformal curvature tensor
S.
Mallick
Department of Mathematics, Chakdaha College, P. O. Chakdaha,
Dist-Nadia, West Bengal, India.
author
P.
Zhao
Department of Applied Mathematics, Nanjing University of Science and Technology,
Nanjing 210094, P. R. China.
author
U. C.
De
Department of Pure Mathematics, University of Calcutta, 35, B. C. Road,
Kolkata 700019, West Bengal, India.
author
text
article
2016
eng
The object of the present paper is to study spacetimes admitting quasi-conformal curvature tensor. At first we prove that a quasi-conformally flat spacetime is Einstein and hence it is of constant curvature and the energy momentum tensor of such a spacetime satisfying Einstein's field equation with cosmological constant is covariant constant. Next, we prove that if the perfect fluid pacetime with vanishing quasi-conformal curvature tensor obeys Einstein's field equation without cosmological constant, then the spacetime has constant energy density and isotropic pressure and the perfect fluid always behave as a cosmological constant and also such a spacetime is infinitesimally spatially isotropic relative to the unit timelike vector field $U$. Moreover, it is shown that in a purely electromagnetic distribution the spacetime with vanishing quasi-conformal curvature tensor is filled with radiation and extremely hot gases. We also study dust-like fluid spacetime with vanishing quasi-conformal curvature tensor.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1535
1546
http://bims.iranjournals.ir/article_908_ca47683e2d4c028ece8b6d5e9a07b102.pdf
Parabolic Marcinkiewicz integrals on product spaces
M.
Ali
Department of Mathematics and Statistics,
Jordan University of Science and Technology, Irbid, Jordan.
author
text
article
2016
eng
In this paper, we study the $L^p$ ($1<p<\infty$) boundedness for the parabolic Marcinkiewicz integral when the kernel function $\Omega$ belongs to the class $L(\log L)( \mathbf{S}^{n-1}\times\mathbf{S}^{m-1})$. Our result essentially extend and improve some known results.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1547
1557
http://bims.iranjournals.ir/article_909_0013491d00e3de0fc7b031ab08ae90ab.pdf
Multiplicity result to some Kirchhoff-type biharmonic equation involving exponential growth conditions
S.
Aouaoui
Institut Superieur des Mathematiques Appliquees et de l'Informa-tique de Kairouan, 3100 Kairouan, Tunisia.
author
text
article
2016
eng
In this paper, we prove a multiplicity result for some biharmonic elliptic equation of Kirchhoff type and involving nonlinearities with critical exponential growth at infinity. Using some variational arguments and exploiting the symmetries of the problem, we establish a multiplicity result giving two nontrivial solutions.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1559
1569
http://bims.iranjournals.ir/article_910_d023f48f0b6624872fac7e75929595b5.pdf
Multi-valued operators with respect $wt$-distance on metric type spaces
M.
Demma
Universita degli Studi di Palermo, Dipartimento di Matematica e Informatica, Via Archirafi, 34, 90123 Palermo, Italy.
author
R.
Saadati
Department of Mathematics, Iran University of Science and Technology, Tehran, Iran.
author
P.
Vetro
Universita degli Studi di Palermo, Dipartimento di Matematica e nformatica,
Via Archirafi, 34, 90123 Palermo, Italy.
author
text
article
2016
eng
Recently, Hussain et al., discussed the concept of $wt$-distance on a metric type space. In this paper, we prove some fixed point theorems for classes of contractive type multi-valued operators, by using $wt$-distances in the setting of a complete metric type space. These results generalize a result of Feng and Liu on multi-valued operators.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1571
1582
http://bims.iranjournals.ir/article_911_d68811f58633ed8b4568d0d352c68671.pdf
PPF dependent fixed point theorems for multi-valued mappings in Banach spaces
A.
Farajzadeh
Department of Mathematics, Razi
University, Kermanshah, 67149, Iran.
author
A.
Kaewcharoen
Department of Mathematics, Faculty of Science,
Naresuan University, Phitsanulok 65000, Thailand.
author
S.
Plubtieng
Department of Mathematics, Faculty of Science,
Naresuan University, Phitsanulok 65000, Thailand.
author
text
article
2016
eng
We prove the existence of PPF dependent coincidence points for a pair of single-valued and multi-valued mappings satisfying generalized contractive conditions in Banach spaces. Furthermore, the PPF dependent fixed point and PPF dependent common fixed point theorems for multi-valued mappings are proved.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
42
v.
6
no.
2016
1583
1595
http://bims.iranjournals.ir/article_912_db2a0d67fb7b266903d9fb7c13a66041.pdf