Hyers-Ulam-Rassias stability of a composite
functional equation in various normed spaces
H.
Azadi Kenary
Yasouj University
author
text
article
2013
eng
In this paper, we prove the generalized Hyers-Ulam(or Hyers-Ulam-Rassias ) stability of the following composite functional equation f(f(x)-f(y))=f(x+y)+f(x-y)-f(x)-f(y) in various normed spaces.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
383
403
http://bims.iranjournals.ir/article_418_aed1e9f7f9878d1f0b43d5533e3a8583.pdf
A note on superspecial and maximal curves
A.
Kazemifard
Shahrekord University
author
A.
Naghipour
Shahrekord University
author
S.
Tafazolian
Institute for Advanced Studies in Basic Sciences
author
text
article
2013
eng
In this note we review a simple criterion, due to Ekedahl, for superspecial curves defined over finite fields.Using this we generalize and give some simple proofs for some well-known superspecial curves.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
405
413
http://bims.iranjournals.ir/article_419_6a4faa2252a2fb3c19cfbeaa4eca5fa5.pdf
Contact CR-Warped product submanifolds in Kenmotsu space forms
M.
Atceken
Gaziosmanpasa University, Faculty of Arts and Sciences, Department of Mathematics, 60250 Tokat/TURKEY
author
text
article
2013
eng
Abstract: In the present paper, we give a necessary and sufficient condition for contact CR-warped product to be contact CR-product in Kenmotsu space forms.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
415
429
http://bims.iranjournals.ir/article_420_56f4f671492858923dbce165596202a3.pdf
On the convergence of three-step random iterative procesess with errors
of nonself asymptotically nonexpansive random
mappings
R.
Rashwan
Department of Mathematics, University of Assiut, P.O.Box 71516, Assiut, Egypt
author
D.
Al-Baqeri
Department of
Mathematics, University
of Assiut, P.O.Box 71516, Assiut, Egypt
author
text
article
2013
eng
begin{abstract} In this paper, we prove some strong and weak convergence of three step random iterative scheme with errors to common random fixed points of three asymptotically nonexpansive nonself random mappings in a real uniformly convex separable Banach space. end{abstract}
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
431
453
http://bims.iranjournals.ir/article_421_aa474a911e5779057293406860aac8c4.pdf
Localization operators on homogeneous spaces
R.
Kamyabi Gol
Ferdowsi University of Mashhad
author
F.
Esmaeelzadeh
Ferdowsi University of Mashhad
author
R.
Raisi Tousi
Ferdowsi University of Mashhad
author
text
article
2013
eng
Let $G$ be a locally compact group, $H$ be a compact subgroup of $G$ and $varpi$ be a representation of the homogeneous space $G/H$ on a Hilbert space $mathcal H$. For $psi in L^p(G/H), 1leq p leqinfty$, and an admissible wavelet $zeta$ for $varpi$, we define the localization operator $L_{psi,zeta} $ on $mathcal H$ and we show that it is a bounded operator. Moreover, we prove that the localization operator is in Schatten $p$-class and also it is a compact operator for $ 1leq p leqinfty$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
455
467
http://bims.iranjournals.ir/article_422_8480c0250cbcd89dcc3dc2b6983c19d5.pdf
On pairwise weakly Lindelof bitopological spaces
A.
Kilicman
University Putra Malaysia
author
Z.
Salleh
University Malaysia Terengganu
author
text
article
2013
eng
In the present paper we introduce and study the notion of pairwise weakly Lindelof bitopological spaces and obtain some results. Further, we also study the pairwise weakly Lindelof subspaces and subsets, and investigate some of their properties. It was proved that a pairwise weakly Lindelof property is not a hereditary property.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
469
485
http://bims.iranjournals.ir/article_423_9d5d1804ff1eebe8d009877fcc795014.pdf
On nilpotent and solvable polygroups
H.
Aghabozorgi
Department of Mathematics, Yazd University, Yazd, Iran
author
M.
Jafarpour
Department of Mathematics, Vali-e-Asr University, Rafsanjan, Iran
author
B.
Davvaz
Yazd University
author
text
article
2013
eng
Applications of hypergroups have mainly appeared in special subclasses. One of the important subclasses is the class of polygroups. In this paper, we study the notions of nilpotent and solvable polygroups by using the notion of heart of polygroups. In particular, we give a necessary and sufficient condition between nilpotent (solvable) polygroups and fundamental groups.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
487
499
http://bims.iranjournals.ir/article_424_1382aa8542282fb58e8f5814d16a8370.pdf
Maximum sum element orders of all proper subgroups of
PGL(2, q)
S.
Jafarian Amri
Zanjan University
author
text
article
2013
eng
In this paper we show that if q is a power of a prime p , then the projective special linear group PSL(2, q) and the stabilizer of a point of the projective line have maximum sum element orders among all proper subgroups of projective general linear group PGL(2, q) for q odd and even respectively
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
501
505
http://bims.iranjournals.ir/article_425_131e9bcb13643b18ecd70f5a42b54a7b.pdf
\phi-Amenable and \phi-biflat Banach algebras
Z.
Ghorbani
Depertment of Mathematics-University of Isfahan
author
M.
Lashkarizadeh Bami
Department of Mathematics, University of Isfahan
author
text
article
2013
eng
In this paper we study the concept of ph-biatness ofa Banach algebra A, where ph is a continuous homomorphism on A.We prove that if ph is a continuous epimorphism on A and A hasa bounded approximate identity and A is ph- biat, then A is ph-amenable. In the case where ph is an isomorphism on A we showthat the ph- amenability of A implies its ph-biatness.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
507
515
http://bims.iranjournals.ir/article_426_7cc478cf8c3e322dd9f487c878ba4cfc.pdf
On solubility of groups with finitely many centralizers
M.
Zarrin
University of Kurdistan
author
text
article
2013
eng
For any group G, let C(G) denote the set of centralizers of G.We say that a group G has n centralizers (G is a Cn-group) if |C(G)| = n.In this note, we prove that every ﬁnite Cn-group with n ≤ 21 is soluble andthis estimate is sharp. Moreover, we prove that every ﬁnite Cn-group with|G| < 30n+1519 is non-nilpotent soluble. This result gives a partial answer to aconjecture raised by A. Ashraﬁ in 2000
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
517
521
http://bims.iranjournals.ir/article_427_8d03882cd4079696032e9bedcf5e7396.pdf
Completely coretractable rings
J.
Zemlicka
Department of Algebra
Faculty of Mathematics and Physics, Charles University in Prague,
author
text
article
2013
eng
A module $M$ is said to be coretractable if there exists a nonzero homomorphism of every nonzero factor of $M$ into $M$. We prove that all right (left) modules over a ring are coretractable if and only if the ring is Morita equivalent to a finite product of local right and left perfect rings.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
523
528
http://bims.iranjournals.ir/article_428_5da7b8715fe169e19d3b38146e66c250.pdf
Asymptotic properties of the sample mean in adaptive sequential sampling with multiple selection criteria
A.
Parvardeh
Academic Professor
author
B.
Panahbehagh
Isfahan University of Technology
author
M.
Salehi
Qatar University
author
J.
Brown
University of Canterbury
author
D.
Smith
U.S. Geological Survey
author
text
article
2013
eng
We extend the method of adaptive two-stage sequential sampling toinclude designs where there is more than one criteria is used indeciding on the allocation of additional sampling effort. Thesecriteria, or conditions, can be a measure of the targetpopulation, or a measure of some related population. We developMurthy estimator for the design that is unbiased estimators forthe population mean, and propose another, more efficient,estimator. We investigate asymptotic properties of this estimator.We use a simulation study to investigate design properties of themulti-criteria adaptive sequential sampling scheme and also someestimator properties under the design.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
529
557
http://bims.iranjournals.ir/article_429_0d7fda83d0d219c63685429b4eeea04c.pdf
Biflatness and biprojectivity of Lau product of Banach algebras
A.
Khoddami
Ferdowsi University of Mashhad
author
H.
Ebrahimi Vishki
Ferdowsi University of Mashhad
author
text
article
2013
eng
Amonge other things we give sufficient and necessary conditions for the Lau product of Banachalgebras to be biflat or biprojective.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
559
568
http://bims.iranjournals.ir/article_430_ce7376069c17575dc6d19eeb2e34a06b.pdf
Some results on the polynomial numerical hulls of matrices
H.
Afshin
Department of Mathematics, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.
author
M.
Mehrjoofard
Department of Mathematics, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran.
author
A.
Salemi
Department of Mathematics, Shahid Bahonar University of Kerman, Kerman, Iran.
author
text
article
2013
eng
In this note we characterize polynomial numerical hulls of matrices $A in M_n$ such that$A^2$ is Hermitian. Also, we consider normal matrices $A in M_n$ whose $k^{th}$ power are semidefinite. For such matriceswe show that $V^k(A)=sigma(A)$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
569
578
http://bims.iranjournals.ir/article_431_3ccef3d5fa00a8a7178d1329d9bbcfd6.pdf
Rings in which elements are the sum of an
idempotent and a regular element
N.
Ashrafi
Semnan University
author
E.
Nasibi
Semnan University
author
text
article
2013
eng
Let R be an associative ring with unity. An element a in R is said to be r-clean if a = e+r, where e is an idempotent and r is a regular (von Neumann) element in R. If every element of R is r-clean, then R is called an r-clean ring. In this paper, we prove that the concepts of clean ring and r-clean ring are equivalent for abelian rings. Further we prove that if 0 and 1 are the only idempotents in R, then an r-clean ring is an exchange ring. Also we show that the center of an r-clean ring is not necessary r-clean, but if 0 and 1 are the only idempotents in R, then the center of an r-clean ring is r-clean. Finally we give some properties and examples of r-clean rings
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
39
v.
3
no.
2013
579
588
http://bims.iranjournals.ir/article_432_9133bb4819dd6ac2221c6ba470843a82.pdf