• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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• pp.603-616
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• 1995

Presented in this paper is an algorithm to obtain the intersections of a polyhedral surface composed of triangle facets with a series of parallel planes for extracting machining information from the surface. The change of the topology of the intersection curves is caused by characteristic points of the surface when sectioning the surface with parallel planes. The characteristic points are internal maximum, internal minimum, internal saddle, boundary maximum, boundary minimum, boundary max-saddle, and boundary min-saddle points. The starting points of the intersects are found efficiently and robustly using the characteristic points. The characteristic points as well as the intersection contours can be used to evaluate the machining information for process planning, and to generate NC tool path in CAD/CAM system.

• 한국의류학회지
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• 제47권1호
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• pp.17-34
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• 2023

This study aimed to develop a fitted torso pattern with an improved fit for inverted-triangular males in their twenties. For this study, six torso patterns were collected, compared and evaluated, and a fitted torso pattern was developed using virtual fittings. The research results are as follows. First, the fitted torso pattern received a good rating as a result of the virtual fitting evaluation: waist dart set 2 of the front; the amount of comfort is set at 5 cm around the chest, 4 cm around the waist and 10 cm around the hips. Second, the evaluation of virtual fitting of the development pattern showed that fit evaluation was 4.11/5 points, ease evaluation was 6.53/7 points, and that the stress map and airgap were suitable for the human body. Third, the actual fit evaluation of the development pattern was 4.25/5 points, 6.35/7 points for ease evaluation, and 4.81/5 points for motion evaluation. Fourth, there was no significant difference between the results of the virtual and actual fitting evaluation with the objectivity test. It is therefore possible to apply a pattern developed through a virtual fitting to an actual human body and to confirm the objectivity of the pattern.

• 대한산업공학회지
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• 제21권4호
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• pp.493-506
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• 1995

Presented in this paper is an algorithm to obtain the intersections of a polyhedral surface composed of triangle facets with a series of parallel planes for extracting machining information from the surface. The change of the topology of the intersection curves is caused by characteristic points of the surface when sectioning the surface with parallel planes. The characteristic points are internal maximum, internal minimum, internal saddle, boundary maximum, boundary minimum, boundary max-saddle, and boundary min-saddle points. The starting points of the intersects are found efficiently and robustly using the characteristic points. The characteristic points as well as the intersection contours can be used to evaluate the machining information for process planning, and to generate NC tool path in CAD/CAM system.

• Journal of applied mathematics & informatics
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• 제36권1_2호
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• pp.93-105
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• 2018

There are many metric functions in the plane. In this paper we are to classify the metric functions on the plane using two ways such as using sum of distances between some points when start point and end point is fixed, and using area of transferred triangle consisted of distances between 3 points.

• Journal of applied mathematics & informatics
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• 제11권1_2호
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• pp.283-290
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• 2003

Andras Bezdek proved that if a convex n-gon and n points are given, then the points and the sides of the polygon can be renumbered so that at least[${\frac{n}{3}}$] triangles spanned by the ith point and the ith side (i = 1,2,...n) are mutually non-overlapping. In this paper, we show that at least [${\frac{n}{2}}$] mutually non-overlapping triangles can be constructed. This lower bound is best possible.

• Geosystem Engineering
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• 제21권6호
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• pp.309-317
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• 2018

We employ a three-dimensional indirect boundary element method (BEM) to simulate temperature change around an underground liquefied natural gas storage cavern. The indirect BEM (IBEM) uses fictitious heat source strength on boundary elements as basic variables which are solved from equations of boundary conditions and then used to compute the temperature change at other points in the considered problem domain. The IBEM requires evaluation of singular integration for temperature change due to heat conduction from a constant heat source on a planar (triangular) region. The singularity can be eliminated by a semi-analytical integration scheme. However, it is found that the semi-analytical integration scheme yields sharp temperature gradient for points close to vertices of triangle. This affects the accuracy of heat flux, if they are evaluated by finite difference method at these points. This difficulty can be overcome by a combination of using a direct numerical integration for these points and the semi-analytical scheme for other points distance away from the vertices. The IBEM and the hybrid integration scheme have been verified with an analytic solution and then used to the application of the underground storage.

• 동의신경정신과학회지
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• 제10권1호
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• pp.133-146
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• 1999

First I chose a patient group and a comparative group composed of 23 members each. Then the body temperature differences in these groups was taken with D.I.T.I. The results are as follows. 1. Average body temperature of the Hwa-Byung patient group is $36.6^{\circ}C$ and that of the comparative group is $36.4^{\circ}C$. So there is no meaningful body temperature difference. 2. The hwa-Byung patient group has higher temperature than the comparative group by ${\triangle}T>1.0^{\circ}C$ at the following acupunture points in these body parts upper and lower, left and right, anterior and posterior, trunk and limb. Especially, the body temperature difference was clear in the CV-17 (jun-Joong) and the GV-4(Myung-moon). 3. When the body temperature was compared in the upper and lower part of the back, it had meaningful differences at the upper and lower acupunture points of the back in the Hwa-Byung patient group but not in the comparative group. 4. When the body temperature was compared in the left and right part of the body, its average difference was ${\triangle}T>1.0^{\circ}C$ in the two groups and the result were meaningless. 5. When body temperature was compared in the anterior and posterior part of the body, its average difference was ${\triangle}T>1.0^{\circ}C$ in the two groups and the result were meaningless. 6. When body temperature was compared in the trunk and limb part of the body, its difference in the patient group was meaningful compared with the non-patient group. From the above results, I think that D.I.T.I. could be used to objectively visualize heat sensation of the Hwa-Byung patients and make an objective concept of Han Yul in oriental medicine.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.705-711
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• 2000

This paper presents a fast 3D mesh generation method using a surface based method with a stitching algorithm. This method uses the surface based method since the volume based method that uses 3D Delaunay triangulation can hardly deal with a large scale of scanned points. To reduce the processing time, this method also uses a stitching algorithm: after dividing the whole point data into several sections and performing mesh generation on individual sections, the meshes from several sections are stitched into one mesh. Stitching method prevents the surface based method from increasing the processing time exponentially as the number of the points increases. This method works well with different types of scanned points: a scattered type points from a conventional 3D scanner and a cross-sectional type from CT or MRI.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제16권2호
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• pp.183-192
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• 2013

이 연구에서는 초등학교 수학 교과서에서 삼각형의 내각의 합과 평행선의 성질이 관련 없이 제시되고 있다는 사실을 지적하고, 이를 유클리드 원론의 체계와 현행 교과서의 관련 내용에 대한 고찰을 바탕으로 그 타당성에 대해 논의하였다. 평행선에 대한 엇각과 동위각의 성질은 초등학교 수학의 여러 주제 속에 내재해 있으며, 유클리드 원론의 체계 속에서 삼각형의 내각과 떼어놓고 생각할 수 없는 의미를 가지고 있었다. 이러한 고찰을 통해 두 주제는 관계를 맺어 지도하는 것이 바람직하다는 결론을 얻었다.

• Kyungpook Mathematical Journal
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• 제56권2호
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• pp.583-595
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• 2016

Archimedes showed that for a point P on a parabola X and a chord AB of X parallel to the tangent of X at P, the area S of the region bounded by the parabola X and chord AB is four thirds of the area T of triangle ${\Delta}ABP$. It is well known that the area U formed by three tangents to a parabola is half of the area T of the triangle formed by joining their points of contact. Recently, the first and third authors of the present paper and others proved that among strictly locally convex curves in the plane ${\mathbb{R}}^2$, these two properties are characteristic ones of parabolas. In this article, in order to generalize the above mentioned property $S={\frac{4}{3}}T$ for parabolas we study strictly locally convex curves in the plane ${\mathbb{R}}^2$ satisfying $S={\lambda}T+{\nu}U$, where ${\lambda}$ and ${\nu}$ are some functions on the curves. As a result, we present two conditions which are necessary and sufficient for a strictly locally convex curve in the plane to be an open arc of a parabola.