권호 표지

Bulletin of the Korean Mathematical Society (대한수학회보)

Korean Mathematical Society

  • Bimonthly
  • /
  • 1015-8634(pISSN)
  • /
  • 2234-3016(eISSN)

Aim & Scope

This journal endeavors to publish significant research of broad interests in pure and applied mathematics. One volume is published each year, and each volume consists of six issues (January, March, May, July, September, November).

http://bkms.kms.or.kr/submission KSCI KCI SCOPUS SCI SCIE

Volume 50 Issue 5

  1. Chen, Zong-Xuan;Gao, Shi-An 1415
    https://doi.org/10.4134/BKMS.2013.50.5.1415 PDF KSCI
    We consider the value distribution of a class of the functions analytic in the exterior of a disc and their applications to complex oscillation theory of differential equations with periodic coefficients in the complex plane.
  2. Long, Kai;Wang, Qichuan;Feng, Lianggui 1433
    https://doi.org/10.4134/BKMS.2013.50.5.1433 PDF KSCI
    A ring R is called left morphic if $$R/Ra{\simeq_-}l(a)$$ for every $a{\in}R$. Equivalently, for every $a{\in}R$ there exists $b{\in}R$ such that $Ra=l(b)$ and $l(a)=Rb$. A ring R is called left quasi-morphic if there exist $b$ and $c$ in R such that $Ra=l(b)$ and $l(a)=Rc$ for every $a{\in}R$. A result of T.-K. Lee and Y. Zhou says that R is unit regular if and only if $$R[x]/(x^2){\simeq_-}R{\propto}R$$ is morphic. Motivated by this result, we investigate the morphic property of the ring $$S_n=^{def}R[x_1,x_2,{\cdots},x_n]/(\{x_ix_j\})$$, where $i,j{\in}\{1,2,{\cdots},n\}$. The morphic elements of $S_n$ are completely determined when R is strongly regular.
  3. Lu, Zhongxue;Liu, Zuhan 1441
    https://doi.org/10.4134/BKMS.2013.50.5.1441 PDF KSCI
    In this paper, we consider two-component Bose-Einstein condensates with an internal atomic Josephson junction in the general case, i.e., 0 < p < $\frac{2}{(d-2)^+}$. We prove existence and uniqueness results for the ground states, and obtain some properties of the ground states with large parameters.
  4. Arsenovic, Milos;Shamoyan, Romi F. 1451
    https://doi.org/10.4134/BKMS.2013.50.5.1451 PDF KSCI
    We present various new sharp assertions on multipliers in mixed norm, weighted Hardy and new Lizorkin-Triebel spaces of harmonic functions in higher dimension. Some results are new even in onedimensional case.
  5. Wang, Songmin;Li, Sheng 1471
    https://doi.org/10.4134/BKMS.2013.50.5.1471 PDF KSCI
    In this paper, we study the non-existence of finite order entire solutions of nonlinear differential-difference of the form $$f^n+Q(z,f)=h$$, where $n{\geq}2$ is an integer, $Q(z,f)$ is a differential-difference polynomial in $f$ with polynomial coefficients, and $h$ is a meromorphic function of order ${\leq}1$.
  6. Camacho, L.M.;Gomez, J.R.;Omirov, B.A.;Turdibaev, R.M. 1481
    https://doi.org/10.4134/BKMS.2013.50.5.1481 PDF KSCI
    The paper is devoted to the study of finite dimensional complex evolution algebras. The class of evolution algebras isomorphic to evolution algebras with Jordan form matrices is described. For finite dimensional complex evolution algebras the criterium of nilpotency is established in terms of the properties of corresponding matrices. Moreover, it is proved that for nilpotent $n$-dimensional complex evolution algebras the possible maximal nilpotency index is $1+2^{n-1}$.
  7. Bessa, Mario 1495
    https://doi.org/10.4134/BKMS.2013.50.5.1495 PDF KSCI
    In this short note we prove that if a symplectomorphism $f$ is $C^1$-stably shadowable, then $f$ is Anosov. The same result is obtained for volume-preserving diffeomorphisms.
  8. Cui, Jian;Chen, Jianlong 1501
    https://doi.org/10.4134/BKMS.2013.50.5.1501 PDF KSCI
    A ring R is called linearly McCoy if whenever linear polynomials $f(x)$, $g(x){\in}R[x]{\backslash}\{0\}$ satisfy $f(x)g(x)=0$, there exist nonzero elements $r,s{\in}R$ such that $f(x)r=sg(x)=0$. In this paper, extension properties of linearly McCoy rings are investigated. We prove that the polynomial ring over a linearly McCoy ring need not be linearly McCoy. It is shown that if there exists the classical right quotient ring Q of a ring R, then R is right linearly McCoy if and only if so is Q. Other basic extensions are also considered.
  9. Flaut, Cristina 1513
    https://doi.org/10.4134/BKMS.2013.50.5.1513 PDF KSCI
    In this paper we will study cyclic codes over some special rings: $\mathbb{F}_q[u]/(u^i)$, $\mathbb{F}_q[u_1,{\ldots},u_i]/(u^2_1,u^2_2,{\ldots},u^2_i,u_1u_2-u_2u_1,{\ldots},u_ku_j-u_ju_k,{\ldots})$, and $\mathbb{F}_q[u,v]/(u^i,v^j,uv-vu)$, where $\mathbb{F}_q$ is a field with $q$ elements $q=p^r$ for some prime number $p$ and $r{\in}\mathbb{N}-\{0\}$.
  10. Nguyen, Thi Hong Loan;Nong, Quoc Chinh 1523
    https://doi.org/10.4134/BKMS.2013.50.5.1523 PDF KSCI
    Let (A,m) be a Noetherian local ring and M a finitely generated A-module. The notion of pseudo Buchsbaum module was introduced in [3] as an extension of that of Buchsbaum module. In this paper, we give a condition for the idealization A⋉M of M over A to be pseudo Buchsbaum.
  11. Panigrahi, Trailokya 1531
    https://doi.org/10.4134/BKMS.2013.50.5.1531 PDF KSCI
    In the present investigation, the author introduces two interesting subclasses of normalized meromorphic univalent functions $w=f(z)$ defined on $\tilde{\Delta}:=\{z{\in}\mathbb{C}:1&lt;{\mid}z{\mid}&lt;{\infty}\}$ whose inverse $f^{-1}(w)$ is also univalent meromorphic in $\tilde{\Delta}$. Estimates for the initial coefficients are obtained for the functions in these new subclasses.
  12. Gao, Zhenlong;Fang, Liang 1539
    https://doi.org/10.4134/BKMS.2013.50.5.1539 PDF KSCI
    In this paper, we extend Donsker's invariance principle to the case of random partial sums processes based on a double sequence of row-wise i.i.d. random variables.
  13. Xu, Liguang 1555
    https://doi.org/10.4134/BKMS.2013.50.5.1555 PDF KSCI
    In this paper, some new generalized discrete Halanay inequalities are established. On the basis of these new established inequalities, we obtain the attracting set and the global asymptotic stability of the nonlinear discrete systems. Our results established here extend the main results in [R. P. Agarwal, Y. H. Kim, and S. K. Sen, New discrete Halanay inequalities: stability of difference equations, Commun. Appl. Anal. 12 (2008), no. 1, 83-90] and [S. Udpin and P. Niamsup, New discrete type inequalities and global stability of nonlinear difference equations, Appl. Math. Lett. 22 (2009), no. 6, 856-859].
  14. Wang, Yong 1567
    https://doi.org/10.4134/BKMS.2013.50.5.1567 PDF KSCI
    In this paper, we study the Einstein multiply warped products with a semi-symmetric non-metric connection and the multiply warped products with a semi-symmetric non-metric connection with constant scalar curvature, we apply our results to generalized Robertson-Walker spacetimes with a semi-symmetric non-metric connection and generalized Kasner spacetimes with a semi-symmetric non-metric connection and find some new examples of Einstein affine manifolds and affine manifolds with constant scalar curvature. We also consider the multiply warped products with an affine connection with a zero torsion.
  15. Zhao, Liang 1587
    https://doi.org/10.4134/BKMS.2013.50.5.1587 PDF KSCI
    In this paper, we obtain some gradient estimates for positive solutions to the following nonlinear parabolic equation $$\frac{{\partial}u}{{\partial}t}={\triangle}u-b(x,t)u^{\sigma}$$ under general geometric flow on complete noncompact manifolds, where 0 < ${\sigma}$ < 1 is a real constant and $b(x,t)$ is a function which is $C^2$ in the $x$-variable and $C^1$ in the$t$-variable. As an application, we get an interesting Harnack inequality.
  16. Kim, Chan Yong;Park, Jeonghyeong;Yorozu, Sinsuke 1599
    https://doi.org/10.4134/BKMS.2013.50.5.1599 PDF KSCI
    We show many examples of curves on the unit 2-sphere $S^2(1)$ in $\mathbb{R}^3$ and the unit 3-sphere $S^3(1)$ in $\mathbb{R}^4$. We study whether its curves are Bertrand curves or spherical Bertrand curves and provide some examples illustrating the resultant curves.
  17. Chandoul, Amara;Amar, Hela Ben;Mkaouar, Mohamed 1623
    https://doi.org/10.4134/BKMS.2013.50.5.1623 PDF KSCI
    The aim of this paper is to prove that every quadratic formal power series ${\omega}$ can be expressed as a periodic non-simple continued fraction having period length one.
  18. Yumei, Ma 1631
    https://doi.org/10.4134/BKMS.2013.50.5.1631 PDF KSCI
    This paper generalizes the Aleksandrov problem and Mazur Ulam theorem to the case of $n$-normed spaces. For real $n$-normed spaces X and Y, we will prove that $f$ is an affine isometry when the mapping satisfies the weaker assumptions that preserves unit distance, $n$-colinear and 2-colinear on same-order.
  19. Zhang, Yu;Li, Shengjie 1639
    https://doi.org/10.4134/BKMS.2013.50.5.1639 PDF KSCI
    In this paper, a class of set-valued mappings is introduced, which is called uniformly same-order. For this sort of mappings, some minimax problems, in which the minimization and the maximization of set-valued mappings are taken in the sense of vector optimization, are investigated without any hypotheses of convexity.
  20. Dhara, Basudeb;Kar, Sukhendu;Mondal, Sachhidananda 1651
    https://doi.org/10.4134/BKMS.2013.50.5.1651 PDF KSCI
    Let R be a prime ring, I a nonzero ideal of R, $d$ a derivation of R, $m({\geq}1)$, $n({\geq}1)$ two fixed integers and $a{\in}R$. (i) If $a((d(x)y+xd(y)+d(y)x+yd(x))^n-(xy+yx))^m=0$ for all $x,y{\in}I$, then either $a=0$ or R is commutative; (ii) If $char(R){\neq}2$ and $a((d(x)y+xd(y)+d(y)x+yd(x))^n-(xy+yx)){\in}Z(R)$ for all $x,y{\in}I$, then either $a=0$ or R is commutative.
  21. Kim, Jeongsim;Kim, Jerim 1659
    https://doi.org/10.4134/BKMS.2013.50.5.1659 PDF KSCI
    In this paper, we are concerned with the analysis of the waiting time distribution in the M/M/m retrial queue. We give expressions for the Laplace-Stieltjes transform (LST) of the waiting time distribution and then provide a numerical algorithm for calculating the LST of the waiting time distribution. Numerical inversion of the LSTs is used to calculate the waiting time distribution. Numerical results are presented to illustrate our results.
  22. Choi, Junesang;Rathie, Arjun K.;Srivastava, Hari M. 1673
    https://doi.org/10.4134/BKMS.2013.50.5.1673 PDF KSCI
    The main objective of this paper is to show how one can obtain eleven new and interesting hypergeometric identities in the form of a single result from the old ones by mainly employing the known beta integral method which was recently introduced and used in a systematic manner by Krattenthaler and Rao [6]. The results are derived with the help of a generalization of a well-known hypergeometric transformation formula due to Kummer. Several identities including one obtained earlier by Krattenthaler and Rao [6] follow as special cases of our main results.
  23. Kim, Byung Hak;Lee, Sang Deok;Choi, Jin Hyuk;Lee, Young Ok 1683
    https://doi.org/10.4134/BKMS.2013.50.5.1683 PDF KSCI
    In this paper, we obtain the criteria that the Riemannian manifold B is Einstein or a gradient Ricci soliton from the information of the second derivative of $f$ in the warped product space $R{\times}_fB$ with gradient Ricci solitons. Moreover, we construct new examples of non-Einstein gradient Ricci soliton spaces with an Einstein or non-Einstein gradient Ricci soliton leaf using our main theorems. Finally we also get analogous criteria for the Lorentzian version.
  24. Lu, Dengfeng;Xiao, Jianhai 1693
    https://doi.org/10.4134/BKMS.2013.50.5.1693 PDF KSCI
    In this paper, we consider the biharmonic elliptic systems of the form $$\{{\Delta}^2u=F_u(u,v)+{\lambda}{\mid}u{\mid}^{q-2}u,\;x{\in}{\Omega},\\{\Delta}^2v=F_v(u,v)+{\delta}{\mid}v{\mid}^{q-2}v,\;x{\in}{\Omega},\\u=\frac{{\partial}u}{{\partial}n}=0,\; v=\frac{{\partial}v}{{\partial}n}=0,\;x{\in}{\partial}{\Omega},$$, where ${\Omega}{\subset}\mathbb{R}^N$ is a bounded domain with smooth boundary ${\partial}{\Omega}$, ${\Delta}^2$ is the biharmonic operator, $N{\geq}5$, $2{\leq}q$ < $2^*$, $2^*=\frac{2N}{N-4}$ denotes the critical Sobolev exponent, $F{\in}C^1(\mathbb{R}^2,\mathbb{R}^+)$ is homogeneous function of degree $2^*$. By using the variational methods and the Ljusternik-Schnirelmann theory, we obtain multiplicity result of nontrivial solutions under certain hypotheses on ${\lambda}$ and ${\delta}$.
  25. Wang, Yao;Ren, Yanli 1711
    https://doi.org/10.4134/BKMS.2013.50.5.1711 PDF KSCI
    P. V$\acute{a}$mos called a ring R 2-good if every element is the sum of two units. The ring of all $n{\times}n$ matrices over an elementary divisor ring is 2-good. A (right) self-injective von Neumann regular ring is 2-good provided it has no 2-torsion. Some of the earlier results known to us about 2-good rings (although nobody so called at those times) were due to Ehrlich, Henriksen, Fisher, Snider, Rapharl and Badawi. We continue in this paper the study of 2-good rings by several authors. We give some examples of 2-good rings and their related properties. In particular, it is shown that if R is an exchange ring with Artinian primitive factors and 2 is a unit in R, then R is 2-good. We also investigate various kinds of extensions of 2-good rings, including the polynomial extension, Nagata extension and Dorroh extension.
  26. Lee, Jin Ho;Lee, Kee Young 1725
    https://doi.org/10.4134/BKMS.2013.50.5.1725 PDF KSCI
    In this paper, we compute the images of homotopy groups of various classical Lie groups under the homomorphisms induced by the natural projections from those groups to irreducible symmetric spaces of classical type. We identify that those computations are certain lower bounds of Gottlieb groups of irreducible symmetric spaces. We use the lower bounds to compute some Gottlieb groups.
  27. Kim, Yongsik 1737
    https://doi.org/10.4134/BKMS.2013.50.5.1737 PDF KSCI
    An efficient and stable point collocation scheme based on a meshfree method is studied for the stationary incompressible Navier-Stokes equations. We describe the diffuse derivatives associated with the moving least square method. Using these diffuse derivatives, we propose a point collocation method to fit in solving the Navier-Stokes equations which improves the stability of the direct point collocation scheme. The convergence of the numerical solution is investigated from numerical examples. The driven cavity ow and the backward facing step ow are implemented for the reliability of the scheme. Also, the viscous ow on complicated geometry is successfully calculated such as the ow past a circular cylinder in duct.
  28. Wong, Kok Bin;Wong, Peng Choon 1753
    https://doi.org/10.4134/BKMS.2013.50.5.1753 PDF KSCI
    In this paper, we show that tree products of certain subgroup separable groups amalgamating normal subgroups are cyclic subgroup separable. We then extend this result to certain graph product of certain subgroup separable groups amalgamating normal subgroups, that is we show that if the graph has exactly one cycle and the cycle is of length at least four, then the graph product is cyclic subgroup separable.