권호 표지

Bulletin of the Korean Mathematical Society (대한수학회보)

Korean Mathematical Society

  • Bimonthly
  • /
  • 1015-8634(pISSN)
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  • 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 47 Issue 6

  1. Kwon, Young-Mee;Jeon, In-Tae;Kang, Hye-Jeong 1105
    https://doi.org/10.4134/BKMS.2010.47.6.1105 PDF KSCI
    We consider jump processes which has only downward jumps with size a fixed fraction of the current process. The jumps of the pro cesses are interpreted as crashes and we assume that the jump intensity is a nondecreasing function of the current process say $\lambda$(X) (X = X(t) process). For the case of $\lambda$(X) = $X^{\alpha}$, $\alpha$ > 0, we show that the process X shold explode in finite time, say $t_e$, conditional on no crash For the case of $\lambda$(X) = (lnX)$^{\alpha}$, we show that $\alpha$ = 1 is the borderline of two different classes of processes. We generalize the model by adding a Brownian noise and examine the blow up properties of the sample paths.
  2. Golbasi, Oznur;Koc, Emine 1121
    https://doi.org/10.4134/BKMS.2010.47.6.1121 PDF KSCI
    In the present paper, we extend some well known results concerning derivations of prime rings to generalized derivations for ($\sigma,\tau$)-Lie ideals.
  3. Kumar, Hemant;Kumari, Shilesh 1131
    https://doi.org/10.4134/BKMS.2010.47.6.1131 PDF KSCI
    In the present paper, we evaluate an analytic formula as a solution of Susceptible Infective (SI) model problem for communicable disease in which the daily contact rate (C(N)) is supposed to be varied linearly with population size N(t) that is large so that it is considered as a continuous variable of time t. Again, we introduce some Lie group of operators to make an extension of above analytic formula of the determin-istic epidemics model problem. Finally, we discuss some of its particular cases.
  4. Choi, Yong-Kab;Moon, Hee-Jin 1139
    https://doi.org/10.4134/BKMS.2010.47.6.1139 PDF KSCI
    Let {$X_j,\;j\geq1$} be a strictly stationary $\phi$-mixing sequence of non-degenerate random variables with $EX_1$ = 0. In this paper, we establish a self-normalized weak invariance principle and a central limit theorem for the sequence {$X_j$} under the condition that L(x) := $EX_1^2I{|X_1|{\leq}x}$ is a slowly varying function at $\infty$, without any higher moment conditions.
  5. Kim, Byeong-Moon;Rho, Yoo-Mi 1155
    https://doi.org/10.4134/BKMS.2010.47.6.1155 PDF KSCI
    In this paper, we find the maximum exponent of D ${\times}$ E, the cartesian product of two digraphs D and E on n, n + 2 vertices, respectively for an even integer $n\geq4$. We also characterize the extrema cases.
  6. Camci, Cetin;Hacisalihoglu, H. Hilmi 1163
    https://doi.org/10.4134/BKMS.2010.47.6.1163 PDF KSCI
    We study finite type curve in $R^3$(-3) which lies in a cylinder $N^2$(c). Baikousis and Blair proved that a Legendre curve in $R^3$(-3) of constant curvature lies in cylinder $N^2$(c) and is a 1-type curve, conversely, a 1-type Legendre curve is of constant curvature. In this paper, we will prove that a 1-type curve lying in a cylinder $N^2$(c) has a constant curvature. Furthermore we will prove that a curve in $R^3$(-3) which lies in a cylinder $N^2$(c) is finite type if and only if the curve is 1-type.
  7. Li, Songxiao 1171
    https://doi.org/10.4134/BKMS.2010.47.6.1171 PDF KSCI
    In this paper we obtain some new characterizations for weighted Bergman spaces in the unit ball of $\mathbb{C}^n$.
  8. Jang, Lee-Chae 1181
    https://doi.org/10.4134/BKMS.2010.47.6.1181 PDF KSCI
    q-Volkenborn integrals ([8]) and fermionic invariant q-integrals ([12]) are introduced by T. Kim. By using these integrals, Euler q-zeta functions are introduced by T. Kim ([18]). Then, by using the Euler q-zeta functions, S.-H. Rim, S. J. Lee, E. J. Moon, and J. H. Jin ([25]) studied q-Genocchi zeta functions. And also Y. H. Kim, W. Kim, and C. S. Ryoo ([7]) investigated twisted q-zeta functions and their applications. In this paper, we consider the q-analogue of twisted Lerch type Euler zeta functions defined by $${\varsigma}E,q,\varepsilon(s)=[2]q \sum\limits_{n=0}^\infty\frac{(-1)^n\epsilon^nq^{sn}}{[n]_q}$$ where 0 < q < 1, $\mathfrak{R}$(s) > 1, $\varepsilon{\in}T_p$, which are compared with Euler q-zeta functions in the reference ([18]). Furthermore, we give the q-extensions of the above twisted Lerch type Euler zeta functions at negative integers which interpolate twisted q-Euler polynomials.
  9. Kim, Seon-Hong;Lee, Jung-Hee 1189
    https://doi.org/10.4134/BKMS.2010.47.6.1189 PDF KSCI
    Kim and Park investigated the distribution of zeros around the unit circle of real self-reciprocal polynomials of even degrees with five terms, where the absolute value of middle coefficient equals the sum of all other coefficients. In this paper, we extend some of their results to the same kinds of polynomials with arbitrary many nonzero terms.
  10. Zhou, Wei;Kim, Goan-Su;Shi, Wujie;Tang, C.Y. 1195
    https://doi.org/10.4134/BKMS.2010.47.6.1195 PDF KSCI
    In this paper, we prove a criterion of conjugacy separability of generalized free products of polycyclic-by-finite groups with a non cyclic amalgamated subgroup. Applying this criterion, we prove that certain generalized free products of polycyclic-by-finite groups are conjugacy separable.
  11. Myung, Sung 1205
    https://doi.org/10.4134/BKMS.2010.47.6.1205 PDF KSCI
    In the present article, we investigate the possibility of a real-valued map on the space of tuples of commuting trace-class self-adjoint operators, which behaves like the usual trace map on the space of trace-class linear operators. It turns out that such maps are related with continuous group homomorphisms from the Milnor's K-group of the real numbers into the additive group of real numbers. Using this connection, it is shown that any such trace map must be trivial, but it is proposed that the target group of a nontrivial trace should be a linearized version of Milnor's K-theory as with the case of universal determinant for commuting tuples of matrices rather than just the field of constants.
  12. Huo, Yingying;Kong, Yinying 1213
    https://doi.org/10.4134/BKMS.2010.47.6.1213 PDF KSCI
    Using Ahlfors' covering surface method, some properties on the strong Borel direction of algebroid function of finite order are obtained. The main object of this paper is to prove existence theorem of a strong Borel direction and the existence of filling discs in such direction which briefly extends some results of meromorphic function.
  13. Choi, Hong-Won;Chung, Sang-Kwon;Lee, Yoon-Ju 1225
    https://doi.org/10.4134/BKMS.2010.47.6.1225 PDF KSCI
    Numerical solutions for the fractional differential dispersion equations with nonlinear forcing terms are considered. The backward Euler finite difference scheme is applied in order to obtain numerical solutions for the equation. Existence and stability of the approximate solutions are carried out by using the right shifted Grunwald formula for the fractional derivative term in the spatial direction. Error estimate of order $O({\Delta}x+{\Delta}t)$ is obtained in the discrete $L_2$ norm. The method is applied to a linear fractional dispersion equations in order to see the theoretical order of convergence. Numerical results for a nonlinear problem show that the numerical solution approach the solution of classical diffusion equation as fractional order approaches 2.
  14. Afrouzi, Ghasem A.;Heidarkhani, Shapour;O'Regan, Donal 1235
    https://doi.org/10.4134/BKMS.2010.47.6.1235 PDF KSCI
    In this paper we establish the existence of at least three weak solutions for Neumann doubly eigenvalue elliptic systems driven by a ($p_1,\ldots,p_n$)-Laplacian. Our main tool is a recent three critical points theorem of B. Ricceri.
  15. Kim, Jeong-Sim 1251
    https://doi.org/10.4134/BKMS.2010.47.6.1251 PDF KSCI
    For an M/G/1 processor-sharing queue with batch arrivals, Avrachenkov et al. [1] conjectured that the conditional mean sojourn time is concave. However, Kim and Kim [5] showed that this conjecture is not true in general. In this paper, we show that this conjecture is true if the service times have a hyperexponential distribution.
  16. Cho, Yeol-Je;Kang, Shin-Min;Qin, Xiaolong 1259
    https://doi.org/10.4134/BKMS.2010.47.6.1259 PDF KSCI
    In this paper, we consider an implicit iterative process with errors for an in nite family of strict pseudocontractions. Strong convergence theorems are established in the framework of Banach spaces. The results presented in this paper improve and extend the recent ones announced by many others.
  17. Park, Hee-Sang;Park, Jong-Il;Shin, Dong-Soo 1269
    https://doi.org/10.4134/BKMS.2010.47.6.1269 PDF KSCI
    As the sequel to our previous work [4], we construct a minimal complex surface of general type with $p_g=0$, $K^2=3$ and $H_1$ = $\mathbb{Z}/2\mathbb{Z}$ by using a rational blow-down surgery and $\mathbb{Q}$-Gorenstein smoothing the-ory.
  18. Jang, Sun-Young 1275
    https://doi.org/10.4134/BKMS.2010.47.6.1275 PDF KSCI
    If the Wiener-Hopf $C^*$-algebra W(G,M) for a discrete group G with a semigroup M has the uniqueness property, then the structure of it is to some extent independent of the choice of isometries on a Hilbert space. In this paper we show that if the Wiener-Hopf $C^*$-algebra W(G,M) of a partially ordered group G with the positive cone M has the uniqueness property, then (G,M) is weakly unperforated. We also prove that the Wiener-Hopf $C^*$-algebra W($\mathbb{Z}$, M) of subsemigroup generating the integer group $\mathbb{Z}$ is isomorphic to the Toeplitz algebra, but W($\mathbb{Z}$, M) does not have the uniqueness property except the case M = $\mathbb{N}$.
  19. Choi, Jin-Ho;Kim, Young-Ho;Tanabe, Hiromasa 1285
    https://doi.org/10.4134/BKMS.2010.47.6.1285 PDF KSCI
    We give criterions for a submanifold to be an extrinsic sphere and to be a totally geodesic submanifold by observing some Frenet curves of order 2 on the submanifold. We also characterize constant isotropic immersions into arbitrary Riemannian manifolds in terms of Frenet curves of proper order 2 on submanifolds. As an application we obtain a characterization of Veronese embeddings of complex projective spaces into complex projective spaces.
  20. Hong, Sung-Bok;Lee, Kyung-Hwa 1297
    https://doi.org/10.4134/BKMS.2010.47.6.1297 PDF KSCI
    We construct a family of 3-balls using cones which represent closed orientable 3-manifolds and study twisted face-pairing construction due to Cannon, Floyd and Parry to understand the structure of such manifolds. Moreover, we prove that those manifolds are hyperbolic.
  21. Kim, Ji-Yean;Lee, Kee-Young 1311
    https://doi.org/10.4134/BKMS.2010.47.6.1311 PDF KSCI
    We introduce the concept of cyclic morphisms with respect to a morphism in the category of pairs as a generalization of the concept of cyclic maps and we use the concept to obtain certain sets of homotopy classes in the category of pairs. For these sets, we get complete or partial answers to the following questions: (1) Is the concept the most general concept in the class of all concepts of generalized Gottlieb subsets introduced by many authors until now? (2) Are they homotopy invariants in the category of pairs? (3) When do they have a group structure?.
  22. Lee, Sang-Cheol 1329
    https://doi.org/10.4134/BKMS.2010.47.6.1329 PDF KSCI