• 터널과지하공간
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• 제10권3호
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• pp.301-308
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• 2000

균열모형을 이용하여 압축 하중하에 있는 암석의 비선형 거동을 예측하는 것은 가능하다. 암석내의 균열의 성장은 암석의 이방성을 가져오며, 이러한 이방성의 정도는 단성계수의 변화로 표현될 수 있다. 본 연구에서는 균열의 성장에 따른 탄성계수의 변화를 이론적인 균열모형을 통해 예측하고, 이를 탄성파 속도 시험을 통해 구한 탄성계수와의 비교를 수행하였다. 또한, 균열모형에 사용되는 초기 암석내 존재하는 균열에 대한 정보는 암석표면의 이미지를 분석하여 구하였다.

• 대한수학회논문집
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• 제10권3호
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• pp.545-560
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• 1995

In this paper, we show one family of normal quintic surfaces in $P^3$ which are birationally isomorphic to Enriques surfaces. We prove that the dimension of the moduli space of these Enriques surfaces is 6.

• 대한수학회지
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• 제44권1호
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• pp.35-54
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• 2007

Let $M_c$ = M(2, 0, c) be the moduli space of O(l)-semistable rank 2 torsion-free sheaves with Chern classes $c_1=0\;and\;c_2=c$ on a K3 surface X, where O(1) is a generic ample line bundle on X. When $c=2n\geq4$ is even, $M_c$ is a singular projective variety equipped with a holomorphic symplectic structure on the smooth locus. In particular, $M_c$ has trivial canonical divisor. In [22], O'Grady asks if there is any symplectic desingularization of $M_{2n}$ for $n\geq3$. In this paper, we show that there is no crepant resolution of $M_{2n}$ for $n\geq3$. This obviously implies that there is no symplectic desingularization.

• 대한수학회보
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• 제48권2호
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• pp.377-386
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• 2011

For a smooth algebraic curve C of genus g $\geq$ 4, let $SU_C$(r, d) be the moduli space of semistable bundles of rank r $\geq$ 2 over C with fixed determinant of degree d. When (r,d) = 1, it is known that $SU_C$(r, d) is a smooth Fano variety of Picard number 1, whose rational curves passing through a general point have degree $\geq$ r with respect to the ampl generator of Pic($SU_C$(r, d)). In this paper, we study the locus swept out by the rational curves on $SU_C$(r, d) of degree < r. As a by-product, we present another proof of Torelli theorem on $SU_C$(r, d).

• 대한수학회논문집
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• 제9권4호
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• pp.933-944
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• 1994

Let $\pi : P \to S^4$ be a principal G-bundle over $S^4$ whose the structure group G is a compact, connected, simple Lie group. Since $\pi_3(G) = \pi_4 (BG) = Z$, we can classify the principal bundle $P_k$ over $S^4$ by the map $S^4 \to BG$ of degree k. Atiyah and Jones [2] showed that $C_k = A_k/g^b_k$ is homotopy equivalent to $\Omega^3_k G \simeq \Omega^4_k BG$ where $A_k$ is the space of the all connections in $P_k$ and $g^b_k$ is the based gauge group which consists of all base point preserving automorphisms on $P_k$. Here $\Omega^nX$ is the space of all base-point preserving continuous map from $S^n$ to X. Let $M_k$ be the space of based gauge equivalence classes of all connections in $P_k$ satisfying the Yang-Mills self-duality equations, which we call the moduli space of G instantons.

• 대한수학회지
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• 제25권2호
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• pp.259-264
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• 1988

• 대한수학회지
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• 제44권6호
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• pp.1339-1350
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• 2007

Here we consider bihyperelliptic curves, i.e., double covers of hyperelliptic curves. By applying the theory of quadruple covers, among other things we prove that the bihyperelliptic locus in the moduli space of smooth curves is irreducible and unirational $g{\geq}4{\gamma}+2{\geq}10$.

• 대한수학회지
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• 제47권1호
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• pp.41-62
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• 2010

In this article, we discuss a Grobner basis algorithm related to the stability of algebraic varieties in the sense of Geometric Invariant Theory. We implement the algorithm with Macaulay 2 and use it to prove the stability of certain curves that play an important role in the log minimal model program for the moduli space of curves.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.132-135
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• 2009

In order study, experimental stress-strain relationships were achieved for various suctions by triaxial tests. A failure envelop was occurred on a plane in p-q-$\psi$ space, since the level of matric suction is in the small range. It was found that the failure criteria could be defined uniquely by the Bishop stress and were also independent of matric suctions. At the level of small strain, deformation moduli were evaluated according to matric suctions by fitting to Ramberg-Osgood model. It was found that deformation moduli increase as matric suctions increase.

• 대한수학회지
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• 제37권2호
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• pp.193-223
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• 2000

In the late 1970's, M. Kuranishi proposed to control the moduli of the germ of a normal Stein space by deformations of the CR structure on the boundary. I this paper, we will see that it is naturally accomplished by considering stably embeddable deformations of CR structures.