• Communications of the Korean Mathematical Society
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• v.11 no.3
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• pp.569-573
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• 1996

We study some special cases of Chow groups of a ramified complete regular local ring R of dimension n. We prove that (a) for codimension 3 Gorenstein ideal I, [I] = 0 in $A_{n-3}(R)$ and (b) for a particular class of almost complete intersection prime ideals P of height i, [P] = 0 in $A_{n-i}(R)$.

• Journal of the Korean Mathematical Society
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• v.37 no.2
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• pp.297-308
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• 2000

We survey results, obtained in the past three years, on characterizing bounded (and Kobayashi-hyperbolic) Reinhardt domains by their automorphism groups. Specifically, we consider the following two situations: (i) the group is non-compact, and (ii) the dimension of the group is sufficiently large. In addition, we prove two theorems on characterizing general hyperbolic complex manifolds by the dimensions of their automorphism groups.

• Journal of applied mathematics & informatics
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• v.28 no.3_4
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• pp.1017-1023
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• 2010

We prove that a maximal ideal M of D[x] has two generators and is of the form where p is an irreducible element in a PID D having infinitely many nonassociate irreducible elements and q(x) is an irreducible non-constant polynomial in D[x]. Moreover, we find how minimal generators of maximal ideals of a polynomial ring D[x] over a DVR D consist of and how many generators those maximal ideals have.

• Journal of the Chungcheong Mathematical Society
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• v.7 no.1
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• pp.53-58
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• 1994

In this note, we study conditions under which SF-rings are semi-simple. We prove that left SF-rings are semisimple for each of the following classes of rings: (1) left non-singular rings of finite rank; (2) rings whose maximal left ideals are finitely generated; (3) rings of pure global dimension zero and (4) rings which is pure-split. Also it is shown that left SF-rings without zero-divisors are semisimple.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.12
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• pp.1934-1939
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• 1989

The circular microstrip resonator which can be exactly performed with theoretical resonant frequency using the conception of dynamic effective relative dielectric constants is analyzed in this paper. The formula of exact resonant frequency of resonator, in this study, is estabilished by effective resonator dimension and dynamic relative dielectric constant. The measurement of transmission type circular resonator which fabricated by AL2O3 and Epsilam-10 is to prove that the experimental results are more agreed a well with the simulated values by this new method than the simple resonator model.

• Journal of the Korean Mathematical Society
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• v.42 no.3
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• pp.471-484
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• 2005

We study Riemannian or pseudo-Riemannian manifolds which carry the space of closed conformal vector fields of at least 2-dimension. Subject to the condition that at each point the set of closed conformal vector fields spans a non-degenerate subspace of the tangent space at the point, we prove a global and a local classification theorems for such manifolds.

• Bulletin of the Korean Mathematical Society
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• v.36 no.2
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• pp.395-402
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• 1999

We introduce the notion of strongly k-disk homogeneous apace and establish a characterization theorem. More specifically, we prove that any analytic Riemannian manifold (M,g) of dimension n which is strongly k-disk homogeneous with 2$\leq$k$\leq$n-1 is a space of constant curvature. Its K hler analog is obtained. The total mean curvature homogeneity of geodesic sphere in k-disk is also considered.

• Bulletin of the Korean Mathematical Society
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• v.56 no.6
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• pp.1447-1465
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• 2019

In this paper, the relativistic Vlasov-Klein-Gordon system in one dimension is investigated. This non-linear dynamics system consists of a transport equation for the distribution function combined with Klein-Gordon equation. Without any assumption of continuity or compact support of any initial particle density $f_0$, we prove the existence and uniqueness of the mild solution via the iteration method.

• Bulletin of the Korean Mathematical Society
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• v.58 no.3
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• pp.537-557
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• 2021

In this paper, we investigate the curvature behavior of complete noncompact gradient expanding Ricci solitons with nonnegative Ricci curvature. For such a soliton in dimension four, it is shown that the Riemann curvature tensor and its covariant derivatives are bounded. Moreover, the Ricci curvature is controlled by the scalar curvature. In higher dimensions, we prove that the Riemann curvature tensor grows at most polynomially in the distance function.

• Bulletin of the Korean Mathematical Society
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• v.56 no.2
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• pp.399-406
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• 2019

Let n be the spatial dimension. For d, $0<d{\leq}n$, let $H^d$ be the d-dimensional Hausdorff content. The purpose of this paper is to prove the boundedness of the dyadic strong maximal operator on the Choquet space $L^p(H^d,{\mathbb{R}}^n)$ for min(1, d) < p. We also show that our result is sharp.