• Journal of Korean Society for Geospatial Information Science
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• v.20 no.4
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• pp.117-125
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• 2012

Although many studies have been conducted to extract buildings from airborne lidar data, most of them assume that all the boundaries of a building are straight line segments. This makes it difficult to model building boundaries containing curved segments correctly. This paper aims to model buildings containing curved segments as combination of straight lines and arcs. First, two sets of boundary points are extracted by adaptive convex hull algorithm and local convex hull algorithm with a larger radius. Then, arc segments are determined by average spacing of boundary points and intersection ratio of perpendicular lines. Finally, building boundary is modeled through regularization of least squares line or circle fitting. The experimental results showed that the proposed method can model the curved building boundaries as arc segments correctly by completeness of 69% and correctness of 100%. The approach will be utilized effectively to create automatically digital map that meets the conditions of the Korean digital mapping.

• Journal of the Korean Society for Railway
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• v.12 no.4
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• pp.597-603
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• 2009

In this study, Based on the optimization developed in Um et al. (2009), optimum design method of the alignment when building new lines and renewing existing ones is presented. The object function used for optimization is passenger comfort ($P_{CT}$) which was proposed in BSI (2006). Other aspects of track/vehicle interaction will be treated in boundary conditions. And track/vehicle interaction analysis is peformed using KTX-II model. From the analysis results, it was found that the optimum alignments are affected by the angle (I) between adjacent straight lines and $R-L_t$ combinations. Also the dynamic analysis confirms well the results from the simplified analysis. However, In the most cases, the $P_{CT}$ values in the dynamic analysis are higher than the simplified $P_{CT}$ values. If both methods are used when optimizing the alignment, it will be possible to design the alignments more rapidly and reliably.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.124-136
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• 2019

Autonomous driving at intersections requires assistance by exchanging traffic information between traffic objects due to the intersection of various vehicles and complicated driving environment. For this reason, traffic information exchange between adjacent intersections is required, but the node ID representing the intersection in the Korean standard node link system have limitations in updating intersections and identifying location information of intersections through IDs due to the configuration system including serial numbers. In this paper, we designed a coordinate-based intersection ID configuration system created by processing and merging two-dimensional coordinates of intersections to include location information in the intersection ID. In order to verify the applicability of the proposed intersection ID, we applied a new intersection ID to domestic intersections and confirmed that there are no duplicate values. Coordinate-based intersection ID reduces data size by 60% compared to existing node ID, and enables spatial queries such as searching for nearby intersections and extracting intersections in specific areas in the form of boxes without GIS tools. Therefore, coordinate-based intersection ID is expected to be more scalable and utilized than existing node ID.

• Journal of Korean Society of Transportation
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• v.29 no.6
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• pp.17-23
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• 2011

It has been presumed that the amount of vehicle's $CO_2$ emission would highly related to vehicle's cruising speeds on highways. In this study, it was tested if vehicle's $CO_2$ emissions would relate to the types of highways and the level of congestion. The results showed that the amount of $CO_2$ emission changes depending on (1) the vehicles' cruising speeds (b) congestion levels, and (c) the types of intersections. It was found that the vehicle acceleration and deceleration methods increases the amount of $CO_2$ emission up to 12%. It was also found that it changed up to 30% and 40% depending on the level of congestion and the types of intersections, respectively. The findings imply that the amount of $CO_2$ emission from vehicles should be improved when vehicles' cruising speeds are well managed through congestion management.

• Food Science of Animal Resources
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• v.20 no.3
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• pp.231-235
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• 2000

원유에 존재하는 Ps. fluorescens의 균수를 신속하게 측정하기 위한 Inhibition Enzyme Linked Immunosorbant Assay (ELSIA)를 개발하기 위해 Ps, fluorescens(KCTC 2344)을 산란계에 접종하여 Ps.fluorescens에 대한 anti-Ps. fluorescens IgY 항체를 생산하고 그 항체의 역기를 ELISA로 측정한 결과 32일까지 항체 역가가 증가하였으며, 분리된 IgY 항체의 titer는 1:128,000으로 나타났다. Anti-Ps.fluorescens IgY 항체에대한 교차반응을 조사한 결과 그람양성균 Lactococcus faecalis, Staphylococcus aureus 뿐만 아니라 그람음성 균인 Achrombacter sal-monisida, Escherichia coil와도 교차반응을 거의 하지 않는 것으로 나타났다. Anti-Ps. fluo-rescens IgY 항체를 가지고 Inhibition ELISA 방법으로 Ps. fluorescens 균수를 신속한 측정할 수 있는 표준곡선을 작성한 결과 Ps. fluorescens균을 5.0$\times$$10^4$cfu/ml부터 5.0$\times$$10^{8}$cfu/ml 측정할 수 있는 것으로 나타났다.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.574-576
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• 1999

변형방법은 물체의 일부분 혹은 전체를 사용자가 원하는 결과의 형태로 변형하는 것으로서, 복잡하고 다양한 자유 형태 곡면들을 모델링하는데 필수적인 방법이다. 이러한 객체들을 제어하기 위한 기존의 방법은 접선벡터와 경계 교차 곡선들로 구성되는 패치들을 정의하고, 물체상의 이동된 점들에 대한 변화량을 계산하기 위하여 많은 계산량이 필요한 문제점이 있었다. 본 논문에서는 분할 경계 패치들을 이용하여 이러한 문제점들을 해결한 새로운 구간 변형 방법을 제시한다. 이 방법은 물체상의 변화량을 분할 경계 곡선에 필요한 형태 제어점으로 간주하여 형태 제어점을 이용하여 불규칙한 패치들을 계산하고 이를 이용하여 접속과 제어 및 국부수정의 변형 제어 방법을 제안한다. 또한 NURBs 보간을 이용하여 변형범위를 효과적으로 제어할 수 있는 방법을 제시한다.

• Korean Journal of Computational Design and Engineering
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• v.3 no.2
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• pp.127-134
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• 1998

This paper presents d new algorithm to compute the offlet curve of a given planar parametric curve. We reduce the problem of computing an offset curve to that of intersecting a surface to a paraboloid. Given an input curve C(t)=(x(t), y(t))∈R², the corresponding surface D/sub c(t)/ is constructed symbolically as the envelope surface of a one-parameter family of tangent planes of the paraboloid Q:z=x²+y²along a lifted curve C(t)=(x(t), y(t), x(t)²+y(t)²∈Q. Given an offset distance d∈R, the offset curve C/sub d/(t) is obtained by the projection of the intersection curve of D/sub c(t)/ and a paraboloid Q:z=x²+y²-d² into the xy-plane.

• Korean Journal of Computational Design and Engineering
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• v.5 no.4
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• pp.336-346
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• 2000

This paper presents a geometric method that can detect and compute all conic sections in the intersection of two tori. Conic sections contained in a torus must be circles. Thus, when two tori intersect in a conic section, the intersection curve must be a circle as well. Circles in a torus are classified into profile circles, cross-sectional circlet, and Yvone-Villarceau circles. Based on a geometric classification of these circles, we present a procedural method that can detect and construct all intersection circles between two tori. All computations can be carried out using simple geometric operations only: e.g., circle-circle intersections, circle-line intersections, vector additions, and inner products. Consequently, this simple structure makes our algorithm robust and efficient, which is an important advantage of our geometric approach over other conventional methods of surface intersection.

• Journal for History of Mathematics
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• v.29 no.5
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• pp.295-314
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• 2016

In tropical geometry, the sum of two numbers is defined as the minimum, and the multiplication as the sum. We learned that dynamic programming in tropical algebraic geometry can be used to find the shortest path in graphs. We have also learned about the Bezout's Theorem, which is a theorem concerning the intersections of tropical plane curves, and the stable intersection principle.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.4
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• pp.32-40
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• 1994

This paper describes a smooth surface interpolating method of ship hull using a three-dimensional currie net that comes from the mesh curve fairing process. Geometric continuity(($GC^1$) is preserved across the boundary curve between patches. The three-dimensional curve net can have nonrectangular topologies, such as triangular and pentagonal topology. Among the boundary curve interpolation methods, Hermite blended Coons patch, Convex combination, and Gregory patch interpolation method are used to generate the ship hull surface. To check the fairness of the surface, the numerical method of surface/surface intersection problem is adopted. An application to an actual ship hull is given as an example.