مرور Volume 43, Issue 7 بر اساس تاریخ انتشار

در حال نمایش موارد 1 - 20 از 34

  • On the fixed number of graphs 

    Javaid, I.؛ Murtaza, M.؛ Asif, M.؛ Iftikhar, F. (Springer and the Iranian Mathematical Society (IMS), 2017-12-01)
    ‎A set of vertices $S$ of a graph $G$ is called a fixing set of $G$‎, ‎if only the trivial automorphism of $G$ fixes every vertex in $S$‎. ‎The fixing number of a graph is the smallest cardinality of a fixing‎ ‎set‎. ‎The ...

  • Distinguishing number and distinguishing index of natural and fractional powers of graphs 

    Alikhani, S.؛ Soltani, S. (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. ...

  • Duality for the class of a multiobjective problem with support functions under $K$-$G_f$-invexity assumptions 

    Debnath, I.P.؛ Gupta, S.K. (Springer and the Iranian Mathematical Society (IMS), 2017-12-01)
    ‎In this article‎, ‎we formulate two dual models Wolfe and Mond-Weir related to symmetric nondifferentiable multiobjective programming problems‎. ‎Furthermore‎, ‎weak‎, ‎strong and converse duality results are established ...

  • The ranks of the classes of $A_{10}$ 

    Basheer, A.B.M‎. (Springer and the Iranian Mathematical Society (IMS), 2017-12-01)
    ‎Let $G $ be a finite group and $X$ be a conjugacy class of $G.$ The‎ ‎rank of $X$ in $G,$ denoted by $rank(G{:}X),$ is defined to‎ ‎be the minimal number of elements of $X$ generating $G.$ In this‎ ‎paper we establish the ...

  • Recurrences and explicit formulae for the expansion and connection coefficients in series of the product of two classical discrete orthogonal polynomials 

    Ahmed, H.M. (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} ...

  • Limits in modified categories of interest 

    Emir, K.؛ Çetin, S. (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 ...

  • Characterization of $2times 2$ full diversity space-time codes and inequivalent full rank spaces 

    Momenaee Kermani, H.؛ Ashenab, M. (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. ...

  • A characterization of orthogonality preserving operators 

    Ansari-piri, E.؛ Sanati, R.G.؛ Kardel, M. (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 ...

  • Modules whose direct summands are FI-extending 

    Tasdemir, O.؛ Karabacak, F. (Springer and the Iranian Mathematical Society (IMS), 2017-12-01)
    ‎A module $M$ is called FI-extending if every fully invariant submodule of $M$ is essential in a direct summand of $M$‎. ‎It is not known whether a direct summand of an FI-extending module is also FI-extending‎. ‎In this ...

  • On subgroups of topologized fundamental groups and generalized coverings 

    Abdullahi Rashid, M.؛ Mashayekhy, B.؛ Torabi, H.؛ Pashaei, S. Z. (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 ...

  • Filter theory in MTL-algebras based on Uni-soft property 

    Muhiuddin, G.؛ Al-roqi, A.M.؛ Aldhafeeri, S. (Springer and the Iranian Mathematical Society (IMS), 2017-12-01)
    ‎The notion of (Boolean) uni-soft filters‎ ‎in MTL-algebras is introduced‎, ‎and several properties of them are‎ ‎investigated‎. ‎Characterizations of (Boolean) uni-soft filters are discussed‎, ‎and some (necessary and ...

  • An extension of the Wedderburn-Artin Theorem 

    Khabazian, H. (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.

  • Improved logarithmic-geometric mean inequality and its application 

    Zou, L. (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.

  • Zero elements and $z$-ideals in modified pointfree topology 

    Estaji, A.A.؛ Karimi Feizabad, A.؛ Zarghani, M. (Springer and the Iranian Mathematical Society (IMS), 2017-12-01)
    ‎In this paper‎, ‎we define and study the notion of zero elements in topoframes; a topoframe is a pair‎ ‎$(L‎, ‎tau)$‎, ‎abbreviated $L_{ tau}$‎, ‎consisting of a frame $L$ and a‎ ‎subframe $ tau $ all of whose elements ...

  • Localization at prime ideals in bounded rings 

    Akalan, E.؛ Saraç, B. (Springer and the Iranian Mathematical Society (IMS), 2017-12-01)
    In this paper we investigate the sufficiency criteria which guarantee the classical localization of a bounded ring at its prime ideals.

  • Characterization of finite $p$-groups by the order of their Schur multipliers ($t(G)=7$) 

    Jafari, S.H. (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 ...

  • Determination of a jump by Fourier and Fourier-Chebyshev series 

    Avdispahic, M.؛ Sabanac, Z. (Springer and the Iranian Mathematical Society (IMS), 2017-12-01)
    ‎By observing the equivalence of assertions on determining the jump of a‎ ‎function by its differentiated or integrated Fourier series‎, ‎we generalize a‎ ‎previous result of Kvernadze‎, ‎Hagstrom and Shapiro to the whole ...

  • Perturbation bounds for $g$-inverses with respect to the unitarily invariant norm 

    Meng, L. (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 ...

  • Solving two-dimensional fractional integro-differential equations by Legendre wavelets‎ 

    Mojahedfar, M.؛ Tari Marzabad, A. (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 ...

  • $L^p$ boundedness of the Bergman projection on some generalized Hartogs triangles 

    Beberok, T. (Springer and the Iranian Mathematical Society (IMS), 2017-12-01)
    ‎In this paper we investigate a two classes of domains in $mathbb{C}^n$ generalizing the Hartogs triangle‎. ‎We prove optimal estimates for the mapping properties of the Bergman projection on these domains.