• 대한수학회보
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• 제51권4호
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• pp.1101-1113
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• 2014

We give analogous criterion to admit a real parabolic connection on real parabolic bundles over a real curve. As an application of this criterion, if real curve has a real point, then we proved that a real vector bundle E of rank r and degree d with gcd(r, d) = 1 is real indecomposable if and only if it admits a real logarithmic connection singular exactly over one point with residue given as multiplication by $-\frac{d}{r}$. We also give an equivalent condition for real indecomposable vector bundle in the case when real curve has no real points.

• 대한수학회지
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• 제57권4호
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• pp.809-823
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• 2020

In this article, we study the deformation theory of locally free sheaves and Hitchin pairs over a nodal curve. As a special case, the infinitesimal deformation of these objects gives the tangent space of the corresponding moduli spaces, which can be used to calculate the dimension of the corresponding moduli space. The deformation theory of locally free sheaves and Hitchin pairs over a nodal curve can be interpreted as the deformation theory of generalized parabolic bundles and generalized parabolic Hitchin pairs over the normalization of the nodal curve, respectively. This interpretation is given by the correspondence between locally free sheaves over a nodal curve and generalized parabolic bundles over its normalization.

• 대한수학회지
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• 제48권3호
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• pp.513-527
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• 2011

The paper deals with the degenerate parabolic system with nonlinear boundary flux. By constructing the self-similar supersolution and subsolution, we obtain the critical global existence curve. The critical Fujita curve is conjectured with the aid of some new results.

• 대한기계학회논문집
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• 제10권3호
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• pp.419-426
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• 1986

본 연구에서는 가공삭도의 선로설계에 최적화기법을 도입하여 시행착오법보다 신속.정확하면서도 경제성이나 승차감등이 항상된 설계를 위한 절차를 개발하고자 한 다. 이를 위하여 먼저 본 논문에서는 설계에 적용될 선로의 기본이론들을 정리, 혹 은 유도 하였다. 특히 기존의 포물곡선이론의 정확성을 규명하기 위하여 엄밀해인 현수곡선이론을 여러경우에 대하여 유도하고 그 오차를 계산하였다. 계산된 오차는 오차해석을 통하여 추측 될 수 있었으며 본 연구에서는 정의된 무차원군들과의 연관 성도 검토되었다.

• 소음진동
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• 제7권2호
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• pp.215-222
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• 1997

The flow and acoustic fields due to a vortex ring interaction with a rigid sphere are simulated numerically. The flow field is regarded as three-dimensional inviscid and incompressible. The vorticity is assumed to be concentrated inside the finite core of vortex filament. The vortex filament curve, described by parabolic blending curve function, is used to effectively solve the modified Biot-Savart equation. The interaction between a vortex ring and a rigid sphere using the parabolic blending curve is calculated. The trajectory of the vortex ring is obtained with several different initial positions between the ring and the sphere. The force variations acting on the sphere are calculated by using the boundary integral method. Finally, we can also obtain the acoustic signals at the far field observation positions from the force variations acting on the rigid surface. We can find that the dipole axis of the directivity patterns are rotated during the interacting phenomena.

• 산업기술연구
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• 제12권
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• pp.69-76
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• 1992

An attempt has been made to determination the NC milling machine's tool-path through the adaptive parabolic interpolation method & the adaptive linear-parabolic interpolation method in consideration of the economical machining time. The algorithms for the above-mentioned interpolation methods have been designed and the numerical experiments for these methods have been conducted with the existing adaptive linear interpolation methods for comparision.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1613-1616
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• 2005

In this paper, we developed an algorithm of generating cam contour curve for hinge mechanism of folder-type mobile phone. The main feature of this hinge mechanism is that we can operate uniform torque to open or close the mobile phone. We divided the opening or closing intervals of the cam into finite sub-intervals, and then we determined the cam contour curve of each sub-interval as a parabolic curve. Finally, these finite parabolic curves form the total cam contour. We can design single cam, which composed moving cam with contour curve and fixed cam that plays only roller, and twin cam with contour curve that is made up the pair of two cams symmetrically.

• 한국조경학회지
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• 제20권4호
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• pp.93-101
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• 1993

The purpose of this study is to analyze th especificity of landscape construction progress in order to develop the model of landscape construction schedule management. Nine case study area in housing complex was selected and the graphic curve of the accumulative payment by landscape construction schedule was analyzed. And the results are as follows: The graphic curve of common construction progress is S-curve but that of landscape construction progress is parabolic-curve, because landscape construction concentrally progress in last period of construction schedule. And particularly parabolic-curve seems to rise up suddenly in the last period when landscape construction amount is small.

• Kyungpook Mathematical Journal
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• 제55권2호
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• pp.473-484
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• 2015

Archimedes determined the center of gravity of a parabolic section as follows. For a parabolic section between a parabola and any chord AB on the parabola, let us denote by P the point on the parabola where the tangent is parallel to AB and by V the point where the line through P parallel to the axis of the parabola meets the chord AB. Then the center G of gravity of the section lies on PV called the axis of the parabolic section with $PG=\frac{3}{5}PV$. In this paper, we study strictly locally convex plane curves satisfying the above center of gravity properties. As a result, we prove that among strictly locally convex plane curves, those properties characterize parabolas.

• 대한수학회지
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• 제61권1호
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• pp.161-181
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• 2024

We describe the moduli space of Higgs pairs on an irreducible nodal curve of arithmetic genus one and its geometric structures in terms of the Hitchin map and a flat degeneration of the moduli space of Higgs bundles on an elliptic curve.