Bulletin of the Iranian Mathematical Society
مرور بر اساس
مجموعههای این پایگاه
ارسال های اخیر
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Limits in modified categories of interest
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)We firstly prove the completeness of the category of crossed modules in a modified category of interest. Afterwards, we define pullback crossed modules and pullback cat objects that are both obtained by pullback ...
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Perturbation bounds for $g$-inverses with respect to the unitarily invariant norm
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)Let complex matrices $A$ and $B$ have the same sizes. Using the singular value decomposition, we characterize the $g$-inverse $B^{(1)}$ of $B$ such that the distance between a given $g$-inverse of $A$ and the set of all ...
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Recurrences and explicit formulae for the expansion and connection coefficients in series of the product of two classical discrete orthogonal polynomials
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)Suppose that for an arbitrary function $f(x,y)$ of two discrete variables, we have the formal expansions. [f(x,y)=sumlimits_{m,n=0}^{infty }a_{m,n},P_{m}(x)P_{n}(y),] $$ x^{m}P_{j}(x)=sumlimits_{n=0}^{2m}a_{m,,n} ...
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An extension of the Wedderburn-Artin Theorem
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)In this paper we give conditions under which a ring is isomorphic to a structural matrix ring over a division ring.
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Characterization of finite $p$-groups by the order of their Schur multipliers ($t(G)=7$)
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)Let $G$ be a finite $p$-group of order $p^n$ and $|{mathcal M}(G)|=p^{frac{1}{2}n(n-1)-t(G)}$, where ${mathcal M}(G)$ is the Schur multiplier of $G$ and $t(G)$ is a nonnegative integer. The classification of such ...
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Existence and convergence results for monotone nonexpansive type mappings in partially ordered hyperbolic metric spaces
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)We present some existence and convergence results for a general class of nonexpansive mappings in partially ordered hyperbolic metric spaces. We also give some examples to show the generality of the mappings considered herein.
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On the existence of Hilbert valued periodically correlated autoregressive processes
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)In this paper we provide sufficient condition for existence of a unique Hilbert valued ($mathbb{H}$-valued) periodically correlated solution to the first order autoregressive model $X_{n}=rho _{n}X_{n-1}+Z_{n}$, ...
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Distinguishing number and distinguishing index of natural and fractional powers of graphs
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)The distinguishing number (resp. index) $D(G)$ ($D'(G)$) of a graph $G$ is the least integer $d$ such that $G$ has an vertex labeling (resp. edge labeling) with $d$ labels that is preserved only by a trivial automorphism. ...
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Characterization of $2times 2$ full diversity space-time codes and inequivalent full rank spaces
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)In wireless communication systems, space-time codes are applied to encode data when multiple antennas are used in the receiver and transmitter. The concept of diversity is very crucial in designing space-time codes. ...
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A characterization of orthogonality preserving operators
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)In this paper, we characterize the class of orthogonality preserving operators on an infinite-dimensional Hilbert space $H$ as scalar multiples of unitary operators between $H$ and some closed subspaces of $H$. We ...
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Nonlinear Picone identities to Pseudo $p$-Laplace operator and applications
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)In this paper, we derive a nonlinear Picone identity to the pseudo p-Laplace operator, which contains some known Picone identities and removes a condition used in many previous papers. Some applications are given including ...
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On the Noetherian dimension of Artinian modules with homogeneous uniserial dimension
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)In this article, we first show that non-Noetherian Artinian uniserial modules over commutative rings, duo rings, finite $R$-algebras and right Noetherian rings are $1$-atomic exactly like $Bbb Z_{p^{infty}}$. ...
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Solving two-dimensional fractional integro-differential equations by Legendre wavelets
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)In this paper, we introduce the two-dimensional Legendre wavelets (2D-LWs), and develop them for solving a class of two-dimensional integro-differential equations (2D-IDEs) of fractional order. We also investigate ...
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On a Picone's identity for the $mathcal{A}_{p(x)}$-Laplacian and its applications
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)We present a Picone's identity for the $mathcal{A}_{p(x)}$-Laplacian, which is an extension of the classic identity for the ordinary Laplace. Also, some applications of our results in Sobolev spaces with ...
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Self-similar solutions of the Riemann problem for two-dimensional systems of conservation laws
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)In this paper, a new approach is applied to study the self-similar solutions of 2×2 systems of nonlinear hyperbolic conservation laws. A notion of characteristic directions is introduced and then used to construct local ...
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Existence and uniqueness of weak solutions for a class of nonlinear divergence type diffusion equations
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)In this paper, we study the Neumann boundary value problem of a class of nonlinear divergence type diffusion equations. By a priori estimates, difference and variation techniques, we establish the existence and ...
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Bounds for the dimension of the $c$-nilpotent multiplier of a pair of Lie algebras
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)In this paper, we study the Neumann boundary value problem of a class of nonlinear divergence type diffusion equations. By a priori estimates, difference and variation techniques, we establish the existence and ...
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Extensions of the Hestenes-Stiefel and Polak-Ribiere-Polyak conjugate gradient methods with sufficient descent property
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)Using search directions of a recent class of three--term conjugate gradient methods, modified versions of the Hestenes-Stiefel and Polak-Ribiere-Polyak methods are proposed which satisfy the sufficient descent condition. ...
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On subgroups of topologized fundamental groups and generalized coverings
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)In this paper, we are interested in studying subgroups of topologized fundamental groups and their influences on generalized covering maps. More precisely, we find some relationships between generalized covering ...
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Improved logarithmic-geometric mean inequality and its application
(Springer and the Iranian Mathematical Society (IMS), 2017-12-01)In this short note, we present a refinement of the logarithmic-geometric mean inequality. As an application of our result, we obtain an operator inequality associated with geometric and logarithmic means.
