• Bulletin of the Korean Mathematical Society
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• v.40 no.3
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• pp.411-423
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• 2003

Some B.-Y. Chen inequalities for different kind of submanifolds of generalized complex space forms are established.

• Journal of the Korean Mathematical Society
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• v.52 no.6
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• pp.1337-1346
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• 2015

We examine the relationship of the shape operator of a surface of Euclidean 3-space with its Gauss map of pointwise 1-type. Surfaces with constant mean curvature and right circular cones with respect to some properties of the shape operator are characterized when their Gauss map is of pointwise 1-type.

• Bulletin of the Korean Mathematical Society
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• v.52 no.1
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• pp.301-312
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• 2015

In this paper, we study a class of spacelike rotational surfaces in the Minkowski 4-space $\mathbb{E}^4_1$ with meridian curves lying in 2-dimensional spacelike planes and having pointwise 1-type Gauss map. We obtain all such surfaces with pointwise 1-type Gauss map of the first kind. Then we prove that the spacelike rotational surface with flat normal bundle and pointwise 1-type Gauss map of the second kind is an open part of a spacelike 2-plane in $\mathbb{E}^4_1$.

• Bulletin of the Korean Mathematical Society
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• v.47 no.4
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• pp.859-881
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• 2010

The helicoidal surface is a generalization of rotation surface in a Minkowski space. We study helicoidal surfaces in a Minkowski 3-space in terms of their Gauss map and provide some examples of new classes of helicoidal surfaces with constant mean curvature in a Minkowski 3-space.

• Communications of the Korean Mathematical Society
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• v.29 no.1
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• pp.141-153
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• 2014

In this article, we apply the weak maximum principle in order to obtain a suitable characterization of the complete linearWeingarten hypersurfaces immersed in locally symmetric Riemannian manifold $N^{n+1}$. Under the assumption that the mean curvature attains its maximum and supposing an appropriated restriction on the norm of the traceless part of the second fundamental form, we prove that such a hypersurface must be either totally umbilical or hypersurface is an isoparametric hypersurface with two distinct principal curvatures one of which is simple.

• Communications of the Korean Mathematical Society
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• v.10 no.2
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• pp.365-374
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• 1995

On a compact manifold without conjugate points, the volume entropy can be obtained as the average mean curvature of the horospheres in the universal covering space. In the case when the volume entropy is zero, we prove that the universal covering space is diffeomorphic to a product space with a line factor. This fact can be considered as a surporting evidence for the Mane's conjecture, which claims the flatness of the mainfold.

• Bulletin of the Korean Mathematical Society
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• v.33 no.1
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• pp.97-106
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• 1996

The study of surface in a Euclidean space whose Gauss map G satisfies the condition : \DeltaG = AG(*)$ for some matrix A was studied by C. Baikoussis, D. E. Blair, B. Y. Chen, F. Dillen, L. Verstraelen ([1]1, [2], [7]) and so on.

• Bulletin of the Korean Mathematical Society
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• v.51 no.5
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• pp.1375-1397
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• 2014

In this paper we establish codimension reduction theorem for submanifolds of a (4m+3)-dimensional unit sphere $S^{4m+3}$ with Sasakian 3-structure and apply it to submanifolds of a quaternionic projective space.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.287-288
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• 2012

DNS is performed to examine the propagation characteristics of stagnating turbulent premixed flames. Results show good agreement with the recently proposed relationship for turbulent burning velocity, $S_T$. It is shown that $S_T$ increases through a thinner flamelet, turbulence production and correlation between fluctuating velocity and buoyancy force respectively for diffusive-thermal, hydrodynamic and Rayleigh-Taylor instability. The mean curvature doesn't have significant effect on $S_T$ at the leading edge.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1997.11a
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• pp.87-90
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• 1997

본 논문에서는 영상의 잡음(noise) 제거를 위한 새로운 diffusion모델을 제안한다. MOD모델 (mean curvature diffusion model)은 영상의 잡음 제거 때 유발되는 경계선의 blurring을 지양할 수 있는 장점이 있는 반면에 수렴상태(convergence state)를 갖지 못한 단점을 안고 있다. 본 논문에서는 MCD 모델에 min/max switch를 결합시킴으로써 MCD모델이 갖고 있던 문제점을 개선하였다. 제안하는 diffusion 모델은 scheme의 반복적인 적용에 대해서 실질적으로 그 결과가 더 이상 변동하지 않는 수렴상태(convergence state)를 가진 매우 안정적인 시스템이다.