فهرست مطالب

Journal of Mathematical Extension
Volume:9 Issue: 2, Spring 2015

  • تاریخ انتشار: 1394/05/20
  • تعداد عناوین: 8
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  • Azam hokmabadi, Marzieh Afkanpoor, Saeed Kayvanfar Pages 1-8

    A group G is called capable if it is isomorphic to the group of inner automorphisms of some group H. The notion of capable groups was extended to capable pairs by G. Ellis, in 1996. Recently, a classification of capable pairs of finite abelian groups was given by A. Pourmirzaei, A. Hokmabadi and S. Kayvanfar. In this paper, we give a different characterization of capable pairs of finite abelian groups in terms of a condition on the lattice of subgroups.

    Keywords: Capability, pairs of groups, finite abeliangroups
  • Sepideh Ebrahimi, S.Talebi Pages 9-25

    We investigate the structure of semi-centralizing and kcommuting maps of module extension algebras. In particular, we give conditions that every semi-centralizing and k-commuting map L of such an algebra is of the form L(c) = cx + h(c), where x lies in the center of the algebra and h is a linear map from the algebra to its center.

    Keywords: Module extension, centralzing map, commutingmap, k-commuting mapp, semi centralzing map, skew-centralizingmap
  • Saeed Ketabchi, Maziar Salahi, Malihe BehboodiKahoo Pages 27-38

    In this paper, we give an algorithm for solving a class of nonconvex quadratic fractional problems that may arise during a correction of inconsistent set of linear inequalities. First, we show that for rank deficient matrices, an optimal solution for a nonconvex fractional minimization problem can be obtained via convex optimization approach. Then an iterative algorithm is designed to solve the problem in the full rank case. Finally, an illustrative numerical example is presented.

    Keywords: Inconsistent linear inequalities, fractionaloptimization, convex optimization
  • Hammad Khalil, Rahmat Ali Khan Pages 39-58

    We study shifted Legendre polynomials and develop some operational matrices of integrations. We use these operational matrices and develop new sophisticated technique for numerical solutions to the following coupled system of fredholm integro differential equations D U(x) = f(x) + 11 Z 1 0 K11(x, t)U(t)dt + 12 Z 1 0 K12(x, t)V (t)dt, D V (x) = g(x) + 21 Z 1 0 K21(x, t)U(t)dt + 22 Z 1 0 K22(x, t)V (t)dt, U(0) = C1, V (0) = C2, where D is fractional derivative of order with respect to x, 0 < 6 1, 11, 12, 21, 22 are real constants, f, g 2 C([0, 1]) and K11, K12, K21, K22 2 C([0, 1]×[0, 1]). We develop simple procedure to reduce the coupled system of equations to a system of algebraic equations without discretizing the system. We provide examples and numerical simulations to show the applicability and simplicity of our results and to demonstrate that the results obtained using the new technique matches well with the exact solutions of the problem. We also provide error analysis.

    Keywords: Legendre polynomials, coupled system, fredholmintegro-differential equations, operational matrices of integrations, numerical
  • Hamidreza Navabpour, Farid Maalek Pages 59-77

    In this paper, a direct analytic method is given for the solution of the linear Fredholm integral and integro-differential equations of the second kind, which is based on the span of the known function, under the action of the operator defined by the kernel. The necessary conditions for using this method are so weak that extends its applicability. The solved examples show the strength of this method.

    Keywords: Fredholm integral equations (FIE), Fredholmintegro-differential equations (FIDE), integral operators, basis functions
  • Hadi Jafari Pages 79-87

    Let (G,N) be a pair of prime power groups. We give a new upper bound for |N G|, where N G is the non-abelian tensor product of N and G. Among other results, the relative Schur multiplier of free product of groups is determined under some conditions.

    Keywords: Non-abelian tensor product, Schur multiplierequation
  • Bahmann Yousefi, S.Talebi, M.Asadipour Pages 89-94

    A bounded linear operator on a Banach space X is called subspace-hypercyclic for a subspace M if Orb(T, x) \ M is dense in M for a vector x 2 M. In this paper we give conditions under which an operator is M-hypercyclic. Then by this result, we answer in the affirmative a question that recently raised by Madore and Martnez- Avendano.

    Keywords: Hypercyclicity, subspace-hypercyclicity
  • Houshang Behravesh Pages 95-103

    V. M. Buchstaber, defined multivalued groups. We define multivalued ring and we show that some similar results in ring theory, hold for multivalued rings.

    Keywords: Multivalued groups, multivalued rings