Bulletin of the Iranian Mathematical Society
text
article
2017
eng
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
http://bims.iranjournals.ir/article_1254_ceede3403839cdf5982d1f99755dc888.pdf
Caratheodory dimension for observers
M.R.
Molaei
Department of Pure Mathematics, Faculty of Mathematics and Computer, Shahid Bahonar University of Kerman, Kerman, Iran.
author
Y.
Sayyari
Department of Pure Mathematics, Faculty of Mathematics and Computer, Shahid Bahonar University of Kerman, Kerman, Iran.
author
text
article
2017
eng
In this essay we introduce and study the notion of dimension for observers via Caratheodory structures and relative probability measures. We show that the dimension as a three variables function is an increasing function on observers, and decreasing function on the cuts of an observer. We find observers with arbitrary non-negative dimensions. We show that Caratheodory dimension for observers is an invariant object under conjugate relations. Caratheodory dimension as a mapping, for multi-dimensional observers is considered. News spread is modeled via multi-dimensional observers.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1559
1570
http://bims.iranjournals.ir/article_1034_60a101abff7a9ba09724f8efa7ac7b21.pdf
On three-dimensional $N(k)$-paracontact metric manifolds and Ricci solitons
U.C.
De
Department of Pure Mathematics, University of Calcutta, 35, Ballygunge Circular Road, Kol- 700019, West Bengal, India.
author
S.
Deshmukh
Department of Mathematics, College of Science, King saud University, P.O. Box-2455, Riyadh-11451, Saudi Arabia.
author
K.
Mandal
Department of Pure Mathematics, University of Calcutta, 35, Ballygunge Circular Road, Kol- 700019, West Bengal, India.
author
text
article
2017
eng
The aim of this paper is to characterize $3$-dimensional $N(k)$-paracontact metric manifolds satisfying certain curvature conditions. We prove that a $3$-dimensional $N(k)$-paracontact metric manifold $M$ admits a Ricci soliton whose potential vector field is the Reeb vector field $xi$ if and only if the manifold is a paraSasaki-Einstein manifold. Several consequences of this result are discussed. Finally, an illustrative example is constructed.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1571
1583
http://bims.iranjournals.ir/article_1040_a446023e2cc7956949c8c04a16793c63.pdf
Decay estimates of solutions to the IBq equation
Y.
Zhang
School of Mathematics and Statistics, North China University of Water Resources and Electric Power, Zhengzhou 450011, China.
author
P.
Li
School of Mathematics and Statistics, North China University of Water Resources and Electric Power, Zhengzhou 450011, China.
author
text
article
2017
eng
In this paper we focus on the Cauchy problem for the generalized IBq equation with damped term in $n$-dimensional space. We establish the global existence and decay estimates of solution with $L^q(1\leq q\leq 2)$ initial value, provided that the initial value is suitably small. Moreover, we also show that the solution is asymptotic to the solution $u_L$ to the corresponding linear equation as time tends to infinity. Finally, asymptotic profile of the solution $u_L$ to the linearized problem is also discussed.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1585
1600
http://bims.iranjournals.ir/article_1038_738b44c2e71a0ee521ae3bc6352b4008.pdf
Functional identities of degree 2 in CSL algebras
D.
Han
School of Mathematics and Information Science, Henan Polytechnic University, Jiaozuo, 454000, P.R. China.
author
text
article
2017
eng
Let $\mathscr{L}$ be a commutative subspace lattice generated by finite many commuting independent nests on a complex separable Hilbert space $\mathbf{H}$ with ${\rm dim}\hspace{2pt}\mathbf{H}\geq 3$, ${\rm Alg}\mathscr{L}$ the CSL algebra associated with $\mathscr{L}$ and $\mathscr{M}$ be an algebra containing ${\rm Alg}\mathscr{L}$. This article is aimed at describing the form of additive mapppings $F_1, F_2, G_1, G_2\colon {\rm Alg}\mathscr{L}\longrightarrow \mathscr{M}$ satisfying functional identity $F_1(X)Y+F_2(Y)X+XG_2(Y)+YG_1(X)=0$ for all $X, Y\in {\rm Alg}\mathscr{L}$. As an application generalized inner biderivations and commuting additive mappings are determined.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1601
1619
http://bims.iranjournals.ir/article_1035_743a4e08ff10b2e3cd9fa16b23cc1eae.pdf
The length of Artinian modules with countable Noetherian dimension
M.
Davoudian
Department of Mathematics, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
author
O.
Ghayour
Department of Mathematics, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
author
text
article
2017
eng
It is shown that if $M$ is an Artinian module over a ring $R$, then $M$ has Noetherian dimension $\alpha $, where $\alpha $ is a countable ordinal number, if and only if $\omega ^{\alpha }+2\leq \it{l}(M)\leq \omega ^{\alpha +1}$, where $ \it{l}(M)$ is the length of $M$, $i.e.,$ the least ordinal number such that the interval $[0, \ \it{l}(M))$ cannot be embedded in the lattice of all submodules of $M$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1621
1628
http://bims.iranjournals.ir/article_1042_3a9a8677dfa67377a62a97351e3a6e04.pdf
On derivations and biderivations of trivial extensions and triangular matrix rings
N.M.
Ghosseiri
Department of Mathematics, University of Kurdistan, P.O. Box 416, Sanandaj, Iran.
author
text
article
2017
eng
Triangular matrix rings are examples of trivial extensions. In this article we determine the structure of derivations and biderivations of the trivial extensions, and thereby we describe the derivations and biderivations of the upper triangular matrix rings. Some related results are also obtained.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1629
1644
http://bims.iranjournals.ir/article_1044_21e6b15378858865b24096a56c02831e.pdf
Two-geodesic transitive graphs of prime power order
W.
Jin
School of Statistics,
Jiangxi University of Finance and Economics,
Nanchang, Jiangxi, 330013, P.R. China | Research Center of Applied Statistics,
Jiangxi University of Finance and Economics,
Nanchang, Jiangxi, 330013, P.R. China.
author
text
article
2017
eng
In a non-complete graph $\Gamma$, a vertex triple $(u,v,w)$ with $v$ adjacent to both $u$ and $w$ is called a $2$-geodesic if $uneq w$ and $u,w$ are not adjacent. The graph $\Gamma$ is said to be $2$-geodesic transitive if its automorphism group is transitive on arcs, and also on 2-geodesics. We first produce a reduction theorem for the family of $2$-geodesic transitive graphs of prime power order. Next, we classify such graphs which are also vertex quasiprimitive.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1645
1655
http://bims.iranjournals.ir/article_1045_dfcf1e1367b8d9455343433f1e659a9c.pdf
Stability of F-biharmonic maps
S.M.
Kazemi Torbaghan
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran.
author
M.M.
Rezaii
Department of Mathematics and Computer Science, Amirkabir University of Technology, Tehran, Iran.
author
text
article
2017
eng
This paper studies some properties of F-biharmonic maps between Riemannian manifolds. By considering the first variation formula of the F-bienergy functional, F-biharmonicity of conformal maps are investigated. Moreover, the second variation formula for F-biharmonic maps is obtained. As an application, instability and nonexistence theorems for F-biharmonic maps are given.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1657
1669
http://bims.iranjournals.ir/article_1049_6c770288ef08175535eb53634c6ca3a0.pdf
Gorenstein hereditary rings with respect to a semidualizing module
G.
Zhao
Department of Mathematics,
Hangzhou Dianzi University,
Hangzhou, 310018, P.R. China.
author
B.
Zhang
School of Mathematics and Information Science,
Henan Polytechnic University, Jiaozuo, 454000, P.R. China.
author
text
article
2017
eng
Let $C$ be a semidualizing module. We first investigate the properties of finitely generated $G_C$-projective modules. Then, relative to $C$, we introduce and study the rings over which every submodule of a projective (flat) module is $G_C$-projective (flat), which we call $C$-Gorenstein (semi)hereditary rings. It is proved that every $C$-Gorenstein hereditary ring is both coherent and $C$-Gorenstein semihereditary.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1671
1677
http://bims.iranjournals.ir/article_1052_a5c3f63a6c7c776ea5aa5f168bb1c109.pdf
Duality for vector equilibrium problems with constraints
N.L.H.
Anh
Department of Optimization and System Theory, University of Science, Vietnam National University Hochiminh City, 227 Nguyen Van Cu, District 5, Hochiminh City, Vietnam.
author
text
article
2017
eng
In the paper, we study duality for vector equilibrium problems using a concept of generalized convexity in dealing with the quasi-relative interior. Then, their applications to optimality conditions for quasi-relative efficient solutions are obtained. Our results are extensions of several existing ones in the literature when the ordering cones in both the objective space and the constraint space have possibly empty interior.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1679
1694
http://bims.iranjournals.ir/article_1053_eba0fe1a292ed8178692f970c5e4725a.pdf
An upper bound for the regularity of powers of edge ideals
M.
Moghimian
Department of Mathematics, Science and Research Branch, Islamic Azad University (IAU), Tehran, Iran.
author
text
article
2017
eng
A recent result due to Ha and Van Tuyl proved that the Castelnuovo-Mumford regularity of the quotient ring $R/I(G)$ is at most matching number of $G$, denoted by match$(G)$. In this paper, we provide a generalization of this result for powers of edge ideals. More precisely, we show that for every graph $G$ and every $s\geq 1$, $${\rm reg}( R/ I(G)^{s})\leq (2s-1) |E(G)|^{s-1} {\rm match}(G).$$
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1695
1698
http://bims.iranjournals.ir/article_1054_da3531e9ece50748643698a60817cad6.pdf
Properties of matrices with numerical ranges in a sector
D.
Zhang
Department of Mathematics, Shanghai University, Shanghai 200444, China.
author
L.
Hou
Department of Mathematics, Shanghai University, Shanghai 200444, China.
author
L.
Ma
Department of Mathematics, Shanghai University, Shanghai 200444, China.
author
text
article
2017
eng
Let $(A)$ be a complex $(n\times n)$ matrix and assume that the numerical range of $(A)$ lies in the set of a sector of half angle $(\alpha)$ denoted by $(S_{\alpha})$. We prove the numerical ranges of the conjugate, inverse and Schur complement of any order of $(A)$ are in the same $(S_{\alpha})$.The eigenvalues of some kinds of matrix product and numerical ranges of hadmard product, star-congruent matrix and unitary matrix of polar decompostion are also included in the same sector. Furthermore, we extend some inequalities about eigenvalues and singular values and the linear fractional maps to this class of matrices.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1699
1707
http://bims.iranjournals.ir/article_1056_b52b59d9cddfb9e022bc31ed6322b513.pdf
On nuclei of sup-$\Sigma$-algebras
X.
Zhang
School of Mathematical Sciences, South China Normal
University, 510631 Guangzhou, China.
author
Y.
Zhou
School of Mathematical Sciences, South China Normal
University, 510631 Guangzhou, China.
author
text
article
2017
eng
In this paper, algebraic investigations on sup-$\Sigma$-algebras are presented. A representation theorem for sup-$\Sigma$-algebras in terms of nuclei and quotients is obtained. Consequently, the relationship between the congruence lattice of a sup-$\Sigma$-algebra and the lattice of its nuclei is fully developed.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1709
1721
http://bims.iranjournals.ir/article_1057_99be559b2c84987c08fb22e247fad759.pdf
High-accuracy alternating segment explicit-implicit method for the fourth-order heat equation
G.
Guo
School of Mathematics and Systems Science, Beijing University of Aeronautics and Astronautics, Beijing 100191, PR China.
author
S.
Lü
School of Mathematics and Systems Science, Beijing University of Aeronautics and Astronautics, Beijing
100191, China.
author
text
article
2017
eng
Based on a group of new Saul’yev type asymmetric difference schemes constructed by author, a high-order, unconditionally stable and parallel alternating segment explicit-implicit method for the numerical solution of the fourth-order heat equation is derived in this paper. The truncation error is fourth-order in space, which is much more accurate than the known alternating segment explicit-implicit methods. Numerical simulations are performed to show the effectiveness of thepresent method that are in preference to the prior methods.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1723
1737
http://bims.iranjournals.ir/article_1059_993ed41f72e1186dd00628a34c963615.pdf
Applications of convolution and subordination to certain $p$-valent functions
S.
Hussain
Department of Mathematics, COMSATS Institute of
Information Technology Abbotabad, Pakistan.
author
J.
Sokół
Department of Mathematics, Institute of
Mathematics, University of Rzeszow, ul. Rejtana 16A, 35-310 Rzeszow, Poland.
author
U.
Farooq
Department of Mathematics, Government Postgraduate College, Abbottabad, Pakistan.
author
M.
Darus
School of Mathematical Sciences, Faculty of Science and
Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia.
author
T.
Mahmood
Department of Mathematics and Statistics,
International Islamic University Islamabad, Pakistan.
author
text
article
2017
eng
In this paper we considered some new classes of multivalent functions by using Aouf-Silverman-Srivastava operator and derived some important results using convolution and subordination technique. This new class is an extension of a class which introduced before.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1739
1749
http://bims.iranjournals.ir/article_1060_2c675a7b7dd48d7b233b76c37b11a172.pdf
Hölder continuity of solution maps to a parametric weak vector equilibrium problem
P.
Preechasilp
Program in Mathematics, Pibulsongkram Rajabhat University, Phitsanulok, Thailand.
author
R.
wangkeeree
Department of Mathematics,Naresuan University, Phitsanulok, Thailand.
author
text
article
2017
eng
In this paper, by using a new concept of strong convexity, we obtain sufficient conditions for Holder continuity of the solution mapping for a parametric weak vector equilibrium problem in the case where the solution mapping is a general set-valued one. Without strong monotonicity assumptions, the Holder continuity for solution maps to parametric weak vector optimization problems is discussed.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1751
1767
http://bims.iranjournals.ir/article_1065_2e8c10b5f887027ce679d1615238281e.pdf
Hyperbolic surfaces of $L_1$-2-type
P.
Lucas
Departamento de Matemáticas, Facultad de Matemáticas, Universidad de Murcia, 30100 Murcia, Spain.
author
H.F.
Ramírez-Ospina
Departamento de Matemáticas, Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá DC, Colombia.
author
text
article
2017
eng
In this paper, we show that an $L_1$-2-type surface in the three-dimensional hyperbolic space $H^3\subset R^4_1$ either is an open piece of a standard Riemannian product $ H^1(-\sqrt{1+r^2})\times S^{1}(r)$, or it has non constant mean curvature, non constant Gaussian curvature, and non constant principal curvatures.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1769
1779
http://bims.iranjournals.ir/article_1062_5af9f5b2ebe4719b4560a0e48f304949.pdf
The second dual of strongly zero-product preserving maps
A.R.
Khoddami
Faculty of Mathematical Sciences, Shahrood University of Technology, P.O. Box 3619995161-316, Shahrood, Iran.
author
text
article
2017
eng
The notion of strongly Lie zero-product preserving maps on normed algebras as a generalization of Lie zero-product preserving maps are defined. We give a necessary and sufficient condition from which a linear map between normed algebras to be strongly Lie zero-product preserving. Also some hereditary properties of strongly Lie zero-product preserving maps are presented. Finally the second dual of a strongly zero-product, strongly Jordan zero-product and strongly Lie zero-product preserving map on a certain class of normed algebras are investigated.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1781
1790
http://bims.iranjournals.ir/article_1063_7b8628e66b977698b444316e36a92e54.pdf
Classification of solvable groups with a given property
M.
Rezaei
Department of Mathematics, Buein Zahra Technical University, Buein Zahra, Qazvin, Iran.
author
Z.
Foruzanfar
Department of Mathematics, Buein Zahra Technical University, Buein Zahra, Qazvin, Iran.
author
text
article
2017
eng
In this paper we classify all finite solvable groups satisfying the following property P5: their orders of representatives are set-wise relatively prime for any 5 distinct non-central conjugacy classes.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1791
1800
http://bims.iranjournals.ir/article_1064_5e25c91a6bdc31bbd41bfb454b5334ef.pdf
The graph of equivalence classes and Isoclinism of groups
R.
Rezaei
Department of Mathematics, Faculty of Mathematical Sciences, Malayer University, Malayer,
Iran.
author
M.
Varmazyar
Department of Mathematics, Faculty of Mathematical Sciences, Malayer University, Malayer,
Iran.
author
text
article
2017
eng
Let $G$ be a non-abelian group and let $\Gamma(G)$ be the non-commuting graph of $G$. In this paper we define an equivalence relation $\sim$ on the set of $V(\Gamma(G))=G\setminus Z(G)$ by taking $x\sim y$ if and only if $N(x)=N(y)$, where $ N(x)=\{u\in G \ | \ x \textrm{ and } u \textrm{ are adjacent in }\Gamma(G)\}$ is the open neighborhood of $x$ in $\Gamma(G)$. We introduce a new graph determined by equivalence classes of non-central elements of $G$, denoted $\Gamma_E(G)$, as the graph whose vertices are $\{[x] \ | \ x \in G\setminus Z(G)\}$ and join two distinct vertices $[x]$ and $[y]$, whenever $[x,y]\neq 1$. We prove that group $G$ is AC-group if and only if $\Gamma_E(G)$ is complete graph. Among other results, we show that the graphs of equivalence classes of non-commuting graph associated with two isoclinic groups are isomorphic.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1801
1810
http://bims.iranjournals.ir/article_1061_2b7cba5aa6cdb3872025474bf8edf9fb.pdf
Defining relations of a group $\Gamma= G^{3,4}(2,Z)$ and its action on real quadratic field
M.
Ashiq
National University of Sciences and Technology, MCS Campus,
Rawalpindi,\ Pakistan.
author
T.
Imran
Department of mathematics and statistics, Riphah International University, Islamabad, Pakistan.
author
M. A.
Zaighum
Department of Basic Sciences Riphah International University Islamabad, Pakistan.
author
text
article
2017
eng
In this paper, we have shown that the coset diagrams for the action of a linear-fractional group $\Gamma$ generated by the linear-fractional transformations $r:z\rightarrow \frac{z-1}{z}$ and $s:z\rightarrow \frac{-1}{2(z+1)}$ on the rational projective line is connected and transitive. By using coset diagrams, we have shown that $r^{3}=s^{4}=1$ are defining relations for $\Gamma$. Furthermore, we have studied some important results for the action of group $\Gamma$ on real quadratic field $Q(\sqrt{n})$. Also, we have classified all the ambiguous numbers in the orbit.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1811
1820
http://bims.iranjournals.ir/article_1066_6cbc8ab9f3f6e93ee2c811ce21ce6a68.pdf
Entropy of a semigroup of maps from a set-valued view
B.
Hou
College of Mathematics, Jilin university, 130012, Changchun, P. R. China.
author
X.
Wang
College of Mathematics, Jilin university, 130012, Changchun, P. R. China.
author
text
article
1999
eng
In this paper, we introduce a new entropy-like invariant, named Hausdorff metric entropy, for finitely generated semigroups acting on compact metric spaces from a set-valued view and study its properties. We establish the relation between Hausdorff metric entropy and topological entropy of a semigroup defined by Bis. Some examples with positive or zero Hausdorff metric entropy are given. Moreover, some notions of chaos are also well generalized for finitely generated semigroups from a set-valued view.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
1999
1821
1835
http://bims.iranjournals.ir/article_1067_479aa58a4bb53422d87b5956ff62afe4.pdf
Initial coefficients of starlike functions with real coefficients
S.
Kumar
Bharati Vidyapeeth's College of Engineering, Delhi--110063, India.
author
V.
Ravichandran
Department of Mathematics, University of Delhi
Delhi--110 007, India.
author
S.
Verma
Department of Mathematics, University of Delhi,
Delhi--110 007, India.
author
text
article
2017
eng
The sharp bounds for the third and fourth coefficients of Ma-Minda starlike functions having fixed second coefficient are determined. These results are proved by using certain constraint coefficient problem for functions with positive real part whose coefficients are real and the first coefficient is kept fixed. Analogous results are obtained for a general class of close-to-convex functions
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1837
1854
http://bims.iranjournals.ir/article_1068_2d1a93d22ef0d7481f165dcb3825c786.pdf
Classifying pentavalnet symmetric graphs of order $24p$
B.
Ling
School of Mathematics and Computer Sciences, Yunnan Minzu University, Kunming, Yunnan 650504, P.R. China.
author
text
article
2017
eng
A graph is said to be symmetric if its automorphism group is transitive on its arcs. A complete classification is given of pentavalent symmetric graphs of order 24p for each prime p. It is shown that a connected pentavalent symmetric graph of order 24p exists if and only if p=2, 3, 5, 11 or 17, and up to isomorphism, there are only eleven such graphs.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1855
1866
http://bims.iranjournals.ir/article_1069_e6c795ff2cc2616cd81138a8139b0332.pdf
A weak approximation for the Extrema's distributions of Levy processes
A.T.
Payandeh Najafabadi
Department of Mathematical Sciences, Shahid Beheshti
University, G.C. Evin, 1983963113, Tehran, Iran.
author
D.Z.
Kucerovsky
Department of Mathematics and Statistics, University of New
Brunswick, Fredericton, N.B. Canada E3B 5A3.
author
text
article
2017
eng
Suppose that $X_{t}$ is a one-dimensional and real-valued L\'evy process started from $X_0=0$, which ({\bf 1}) its nonnegative jumps measure $\nu$ satisfying $\int_{\Bbb R}\min\{1,x^2\}\nu(dx)<\infty$ and ({\bf 2}) its stopping time $\tau(q)$ is either a geometric or an exponential distribution with parameter $q$ independent of $X_t$ and $\tau(0)=\infty.$ This article employs the Wiener-Hopf Factorization (WHF) to find, an $L^{p^*}({\Bbb R})$ (where $1/{p^*}+1/p=1$ and $1<p\leq2$), approximation for the extrema's distributions of $X_{t}.$ Approximating the finite (infinite)-time ruin probability as a direct application of our findings has been given. Estimation bounds, for such approximation method, along with two approximation procedures and several examples are explored.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1867
1888
http://bims.iranjournals.ir/article_1244_7733deed4511081e9bceedc681ecc11b.pdf
Existence of positive solutions for a second-order p-Laplacian impulsive boundary value problem on time scales
F.
Tokmak Fen
Department of Mathematics, Gazi University, Teknikokullar, 06500 Ankara, Turkey.
author
I.Y.
Karaca
Department of Mathematics, Ege University, Bornova, 35100 Izmir, Turkey.
author
text
article
2017
eng
In this paper, we investigate the existence of positive solutions for a second-order multipoint p-Laplacian impulsive boundary value problem on time scales. Using a new fixed point theorem in a cone, sufficient conditions for the existence of at least three positive solutions are established. An illustrative example is also presented.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1889
1903
http://bims.iranjournals.ir/article_1070_da5504c917fa9b3f5a2cd16c41f2ca5a.pdf
When is the ring of real measurable functions a hereditary ring?
H.
Hejazipour
Department of Mathematical Sciences, Shahrekord University, P.O. Box 115, Shahrekord, Iran.
author
A. R.
Naghipour
Department of Mathematical Sciences, Shahrekord University, P.O. Box 115, Shahrekord, Iran.
author
text
article
2017
eng
Let $M(X, \mathcal{A}, \mu)$ be the ring of real-valued measurable functions on a measure space $(X, \mathcal{A}, \mu)$. In this paper, we characterize the maximal ideals in the rings of real measurable functions and as a consequence, we determine when $M(X, \mathcal{A}, \mu)$ is a hereditary ring.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1905
1912
http://bims.iranjournals.ir/article_1073_1eb98851b6536cbd289da1c626d55f8d.pdf
Subdirectly irreducible acts over some semigroups
Gh.
Moghaddasi
Department of Mathematics, Hakim Sabzevari University, Sabzevar, Iran.
author
M.
Mahmoudi
Department of Mathematics, Shahid Beheshti University, Tehran, Iran.
author
text
article
2017
eng
In this paper, we characterize and find the number of subdirectly irreducible acts over some classes of semigroups, such as zero semigroups, right zero semigroups and strong chain of left zero semigroups.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1913
1924
http://bims.iranjournals.ir/article_1074_23345385ea8c6ec1307ceb3d81b2ed2b.pdf
The lower bound for the number of 1-factors in generalized Petersen graphs
H.
Ren
Department of Mathematics, East China Normal University, Shanghai, 200241, P.R. China|
Shanghai Key Laboratory of PMMP, Shanghai, 200241, P.R. China.
author
C.
Yang
School of Mathematics, Physics and Statistics, Shanghai University of Engineering Science, Shanghai, 201620, P.R. China.
author
J.
Wang
Department of Mathematics, East China Normal University, Shanghai, 200241, P.R. China.
author
text
article
2017
eng
In this paper, we investigate the number of 1-factors of a generalized Petersen graph $P(N,k)$ and get a lower bound for the number of 1-factors of $P(N,k)$ as $k$ is odd, which shows that the number of 1-factors of $P(N,k)$ is exponential in this case and confirms a conjecture due to Lovász and Plummer (Ann. New York Acad. Sci. 576(2006), no. 1, 389-398).
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1925
1937
http://bims.iranjournals.ir/article_1075_cf616b56426d01c35cd3041b4df264ed.pdf
Composition of resolvents and quasi-nonexpansive multivalued mappings in Hadamared spaces
G.
Zamani Eskandani
Department of Pure Mathematics, Faculty of Mathematical Sciences, University of Tabriz, Tabriz, Iran.
author
S.
Azarmi
Department of Pure Mathematics, Faculty of Mathematical Sciences, University of Tabriz, Tabriz, Iran.
author
M.
Eslamian
Department of Mathematics, University of Science and Technology of Mazandaran,
P.O. Box 48518-78195, Behshahr, Iran.
author
text
article
2017
eng
The proximal point algorithm, which is a well-known tool for finding minima of convex functions, is generalized from the classical Hilbert space framework into a nonlinear setting, namely, geodesic metric spaces of nonpositive curvature. In this paper we propose an iterative algorithm for finding the common element of the minimizers of a finite family of convex functions and the common fixed points of a finite family of quasi-nonexpansive multivalued mappings in Hadamard spaces.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1939
1955
http://bims.iranjournals.ir/article_1076_669539101764946143d80ea1280ca7a4.pdf
A hybrid mean value involving a new Gauss sums and Dedekind sums
X.X.
Li
School of Mathematics, Northwest University,
Xi'an, Shaanxi, 710127, P.R. China.
author
W.P.
Zhang
School of Mathematics, Northwest University, Xi'an, Shaanxi, 710127, P.R. China.
author
text
article
2017
eng
In this paper, we introduce a new sum analogous to Gauss sum, then we use the properties of the classical Gauss sums and analytic method to study the hybrid mean value problem involving this new sums and Dedekind sums, and give an interesting identity for it.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1957
1968
http://bims.iranjournals.ir/article_1077_2158a37858112c93483a006a0f583088.pdf
Semi-Rothberger and related spaces
A.
Sabah
Department of Mathematics, COMSATS Institute of Information
Technology, Chack Shahzad, Park Road, Islamabad 45550, Pakistan.
author
M.
Khan
Department of Mathematics, COMSATS Institute of Information
Technology, Chack Shahzad, Park Road, Islamabad 45550, Pakistan.
author
text
article
2017
eng
In this paper our focus is to study certain covering properties in topological spaces by using semi-open covers. A part of this article deals with Rothberger-type covering properties. The notions of s-Rothberger, almost s-Rothberger, star s-Rothberger, almost star s-Rothberger, strongly star s-Rothberger spaces are defined and corresponding properties are investigated.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1969
1987
http://bims.iranjournals.ir/article_1078_9fad6d520d7acfc75e636817ab29dff9.pdf
A descent method for explicit computations on curves
K.
Filom
Department of Mathematical Sciences, Sharif University of Technology, Tehran, Iran.
author
text
article
2017
eng
It is shown that the knowledge of a surjective morphism $X\to Y$ of complex curves can be effectively used to make explicit calculations. The method is demonstrated by the calculation of $j(n\tau)$ (for some small $n$) in terms of $j(\tau)$ for the elliptic curve with period lattice $(1,\tau)$, the period matrix for the Jacobian of a family of genus-$2$ curves complementing the classic calculations of Bolza and explicit general formulae for branched covers of an elliptic curve with exactly one ramification point.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
1989
2016
http://bims.iranjournals.ir/article_1079_545c2bcc6cfdf11ec7739e314d3a881f.pdf
Upper bounds for noetherian dimension of all injective modules with Krull dimension
S.J.
Hashemi Zadeh Dezfuli
Department of Mathematics, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
author
M.
Zholanezhad
Department of Mathematics, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
author
text
article
2017
eng
In this paper we give an upper bound for Noetherian dimension of all injective modules with Krull dimension on arbitrary rings. In particular, we also give an upper bound for Noetherian dimension of all Artinian modules on Noetherian duo rings.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
2017
2025
http://bims.iranjournals.ir/article_1080_f46e865bcb496ef8b2f73ce9509d0735.pdf
Locally finite basic classical simple Lie superalgebras
M.
Yousofzadeh
Department of Mathematics, University of Isfahan, Isfahan, Iran,
P.O. Box 81745-163| School of Mathematics, Institute for Research in
Fundamental
Sciences (IPM), P.O. Box 19395-5746, Tehran, Iran.
author
text
article
2017
eng
In this work, we study direct limits of finite dimensional basic classical simple Lie superalgebras and obtain the conjugacy classes of Cartan subalgebras under the group of automorphisms.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
2027
2050
http://bims.iranjournals.ir/article_1081_09a5fb4afd52490e52e8c06dd7e434b5.pdf
On normalizers of maximal subfields of division algebras
M.
Motiee
Faculty of Basic Sciences, Babol Noshirvani University of Technology, Shariati Ave., Babol, Post Code 47148-71167, Iran.
author
text
article
2017
eng
Here, we investigate a conjecture posed by Amiri and Ariannejad claiming that if every maximal subfield of a division ring $D$ has trivial normalizer, then $D$ is commutative. Using Amitsur classification of finite subgroups of division rings, it is essentially shown that if $D$ is finite dimensional over its center then it contains a maximal subfield with non-trivial normalizer if and only if $D^*$ contains a non-abelian soluble subgroup. This result generalizes a theorem of Mahdavi-Hezavehi and Tignol about cyclicity of division algebras of prime index.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
2051
2056
http://bims.iranjournals.ir/article_1082_46171c8ef1baa76a91c6ee91c20ac491.pdf
Singular values of convex functions of matrices
Z.
Ulukök
Vadi Park Sit., Gulvatan Sok., Yazir, Selçuklu, 42250, Konya, Turkey.
author
text
article
2017
eng
Let $A_{i},B_{i},X_{i},i=1,\dots,m,$ be $n$-by-$n$ matrices such that $\sum_{i=1}^{m}\left\vert A_{i}\right\vert ^{2}$ and $\sum_{i=1}^{m}\left\vert B_{i}\right\vert ^{2}$ are nonzero matrices and each $X_{i}$ is positive semidefinite. It is shown that if $f$ is a nonnegative increasing convex function on $\left[ 0,\infty \right) $ satisfying $f\left( 0\right) =0 $, then $$2s_{j}\left( f\left( \frac{\left\vert \sum_{i=1}^{m}A_{i}^{\ast }X_{i}B_{i}\right\vert }{\sqrt{\left\Vert \sum_{i=1}^{m}\left\vert A_{i}\right\vert ^{2}\right\Vert \left\Vert \sum_{i=1}^{m}\left\vert B_{i}\right\vert ^{2}\right\Vert }}\right) \right) \leq s_{j}\left( \oplus _{i=1}^{m}f\left( 2X_{i}\right) \right)$$ for $j=1,\ldots,n$. Applications of our results are given.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
2057
2066
http://bims.iranjournals.ir/article_1083_327a7a884377fbd11d819f33653250c0.pdf
A new hybrid conjugate gradient algorithm for unconstrained optimization
X.
Han
School of Mathematics and Statistics, Southwest University, Chongqing 400715, P.R. China.
author
J.
Zhang
School of Mathematics and Statistics, Southwest University, Chongqing 400715, P.R. China.
author
J.
Chen
School of Mathematics and Statistics, Southwest University, Chongqing 400715, P.R. China.
author
text
article
2017
eng
In this paper, a new hybrid conjugate gradient algorithm is proposed for solving unconstrained optimization problems. This new method can generate sufficient descent directions unrelated to any line search. Moreover, the global convergence of the proposed method is proved under the Wolfe line search. Numerical experiments are also presented to show the efficiency of the proposed algorithm, especially for solving highly dimensional problems.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
2067
2084
http://bims.iranjournals.ir/article_1084_109497f29bf88715b9cadc58859c6be0.pdf
Some results on pre-monotone operators
M.H.
Alizadeh
Department of Mathematics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran.
author
M.
Roohi
Department of Mathematics, Faculty of Sciences, Golestan University,
P.O. Box 155, Gorgan, Iran.
author
text
article
2017
eng
In this paper, some properties of pre-monotone operators are proved. It is shown that in a reflexive Banach space, a full domain multivalued $\sigma$-monotone operator with sequentially norm$\times$weak$^*$ closed graph is norm$\times$weak$^*$ upper semicontinuous. The notion of $\sigma$-convexity is introduced and the relations between the $\sigma$-monotonicity and $\sigma$-convexity is investigated. Moreover, some results on the sum and difference of two $\sigma$-monotone operators is considered.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
2085
2097
http://bims.iranjournals.ir/article_1085_cc4d2b57b686d6c39e4e826525d95114.pdf
Non-homogeneous continuous and discrete gradient systems: the quasi-convex case
H.
Khatibzadeh
Department of Mathematics, University
of Zanjan, P. O. Box 45195-313, Zanjan, Iran.
author
V.
Mohebbi
Department of Mathematics, University
of Zanjan, P. O. Box 45195-313, Zanjan, Iran.
author
text
article
2017
eng
In this paper, first we study the weak and strong convergence of solutions to the following first order nonhomogeneous gradient system $$\begin{cases}-x'(t)=\nabla\phi(x(t))+f(t),\ \ \ \ \text{a.e.\ \ on}\ (0,\infty)\\x(0)=x_0\in H\end{cases}$$ to a critical point of $\phi$, where $\phi$ is a $C^1$ quasi-convex function on a real Hilbert space $H$ with ${\rm Argmin}\phi\neq\varnothing$ and $f\in L^1(0,+\infty;H)$. These results extend the results in the literature to non-homogeneous case. Then the discrete version of the above system by backward Euler discretization has been studied. Beside of the proof of the existence of the sequence given by the discrete system, someresults on the weak and strong convergence to the critical point of $\phi$ are also proved. These results when $\phi$ is pseudo-convex (therefore the critical points are the same minimum points) may be applied in optimization for approximation of a minimum point of $\phi$.
Bulletin of the Iranian Mathematical Society
Iranian Mathematical Society (IMS)
1017-060X
43
v.
6
no.
2017
2099
2110
http://bims.iranjournals.ir/article_1086_c9f5c603ae165a46745899906352a83b.pdf