• Proceedings of the KSR Conference
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• 2003.05a
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• pp.331-336
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• 2003

본 연구에서는 원형요소를 자동적으로 생성시킬 수 있는 2차원 개별요소법 알고리즘을 개발하였다. 개발된 프로그램으로 다양한 반지름을 갖는 원형요소를 구현할 수 있었고 이를 이용하여 침목하부의 도상자갈을 모델링하였다. 또한 프로그램의 적용성을 확인하기 위하여 중복과 겹침이 없는 원형요소의 자동생성 예제를 개발하였다.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.10-11
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• 2000

광섬유 격자는 WDM 광시스템의 필터뿐만 아니라 센서로도 많은 연구가 되고 있다. 이 경우 필수적인 것이 유효굴절률에 대한 해석이다. 유효굴절률은 광섬유의 코어와 클래딩의 굴절률과 반지름에 따른 수치해석을 통해서도 구할 수 있다. 수치해석과정에서 필수적인 것이 파장에 따른 굴절률을 계산할 수 있는 Sellmeier식이다$^{(1)}$ . 본 연구에서는 광섬유격자 쌍을 이용하여 광섬유의 유효굴절률을 클래딩 모드수에 따라 측정할 수 있는 새로운 방법을 제시한다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.224-225
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• 2003

이 연구에서는 광결정 (photonic crystal) 박막 (slab) 위에 제작된 막대형 공진기의 공진모드의 특성을 보고한다. 먼저 3차원 FDTD 방법을 이용하여 각각의 공진 모드들의 모드 형태, 공진주파수, 품위값(Q factor) 등을 구하였다. 광결정 격자의 주기가 $\alpha$ 일 때, 슬랩의 두께는 0.4 $\alpha$ , 구멍의 반지름은 0.35 $\alpha$ 로 하였다. 슬랩의 굴절률 (n) 은 실험에서 사용한 InP의 1.55 $\mu$m 에서의 굴절률 값인 3.4 로 정하였다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.228-229
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• 2003

광자 크리스탈의 밴드 구조가 다른 물질이 접하는 경계면으로 구성되는 이종 접합 구조(Heteorostructure)는 단일 구조에서 관찰할 수 없는 특성을 보유하고 있으므로 관심을 끌고 있다. 이를 이용한 다 파장 add-drop 필터, 2D-3D 하이브리드 구조에 의한 무 회절 손실 도파로, beam splitter와 combiner 등의 연구 결과가 최근에 제시되었다. 본 논문에서는 positive 굴절율과 negative 굴절율을 갖는 광자 크리스탈이 이종 접합 구조를 형성할 때의 굴절 작용의 변화를 실린더의 반지름 변화에 따라 고찰하였다. (중략)

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.368-369
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• 2020

본 작품은 어떻게 보여줄 것인지에만 치중된 증강현실 개발 환경에서 어떻게 인간과 상호작용 할 것인가에 대한 고민이 부족하다고 생각하여 본 캡스톤디자인을 시작하였다. 손가락에 착용하는 반지형태의 디바이스와 이를 이용한 증강현실 조작 인터페이스를 구현하는 것을 목표로 한다. 이를 위해서 모바일 Video-Through HMD 증강현실 환경을 만든 뒤 증강된 객체의 배치, 이동, 회전과 같은 조작을 구현하였다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.2
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• pp.67-75
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• 2013

The purpose of this study was to collect the basic data on establishing the conservation plan for the domestic wetland through flora and life form analysis at Junam wetland. The vascular plants were recorded as 222 taxa; 58 families, 167 genera, 200 species, 3 subspecies, 1 forma and 18 varieties. Among 8 life forms, Therophytes (Th), Hemicryptophytes (H) and Hydrophytes (HH) showed high percentage, and these species comprised 71.1% of the whole flora at Junam wetland. One taxa (Euryale ferox) rare plants designated by Korea Forest Service were observed. The naturalized plants were 38 taxa including Fallopia dumetora, Oenothera odorata, Ambrosia artemisiifolia var. elatior and so forth, and naturalized ratio was 17.1%. The naturalized made up about 45 percent of the species composition. The specific plants by floristic region were 13 taxa including Euryale ferox., Hydrocharis dubia, Prunus davidiana and so forth.

• Journal of KIISE
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• v.43 no.5
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• pp.562-568
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• 2016

Point cloud data can be expressed in a specific coordinate system of a data set with a large number of points, to represent any form that generally has different characteristics in the three-dimensional coordinate space. This paper is aimed at finding a cylindrical pipe in the point cloud of the three-dimensional coordinate system using RANSAC, which is faster than the conventional Hough Transform method. In this study, the proposed cylindrical pipe is estimated by combining the results of parameters based on two mathematical models. The two kinds of mathematical models include a sphere and line, searching the sphere center point and radius in the cylinder, and detecting the cylinder with straightening of center. This method can match cylindrical pipe with relative accuracy; furthermore, the process is rapid except for normal estimation and segmentation. Quick cylinders matching could benefit from laser scanning and reverse engineering construction sectors that require pipe real-time estimates.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.492-498
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• 2017

This study examined the bending performance of high strength and seismic purpose reinforcing bars experimentally with various parameters. For the experimental approach on the bending performance, the specimens were prepared with parameters, such as steel grades, diameters of reinforcing bars, and bending angles of reinforcing bars. Tensile strength tests on the reinforcing bars, the bending tests and re-bending tests, and the second tensile strength tests on the re-bended reinforcing bars were conducted. According to the test results on high strength and seismic purpose reinforcing bars, defects did not appear when the yield strength of the reinforcing bar was 500 MPa or less and the diameter was D13 or less, even when the first bending process was performed with a $135^{\circ}$ bending angle and a $2d_b$ inner radius. The bending performance decreased asthe strength and diameter of the reinforcing bars was increased. In addition, there was no significant difference between the general reinforcing bars and seismic purpose-reinforcing bars.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.10
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• pp.895-900
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• 2013

A two-dimensional Stokes flow past a circular cylinder in a channel is analyzed. The circular cylinder is located at the center of the channel, and a plane Poiseuille flow exists upstream and downstream far from the circular cylinder. The Stokes approximation is used, and the flow is investigated analytically by using the eigenfunction expansion and the least square methods. From the analysis, the stream function and pressure distribution are obtained, and the pressure and shear stress distributions on the circular cylinder and channel wall are calculated. The additional pressure drop induced by the circular cylinder and the force exerted on it are calculated as functions of the length of the radius of the circular cylinder. For a typical length of the radius of the circular cylinder, the streamline pattern and pressure distribution are shown.

• Archives of design research
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• v.18 no.1 s.59
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• pp.157-166
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• 2005

The purpose of the study is to understand the symbolic meaning of jewelry. Among various characteristics of symbols, the symbolic meaning represents the correlation between meanings. Wearing jewelry is an instinctive action that can be witnessed from ancient civilizations. Man used jewelry for various purposes, as an ornament, an amulet, a symbol of wealth or power or as a token of love. In this study, I have researched the symbolic meaning of jewelry in its historic background focusing on rings that show the strongest symbolic characteristic among jewelries. Whereas the symbolic meaning of jewelry was strongly accentuated in the ancient and medieval times, it was gradually weakened in the modern time. Also, while jewelry in the ancient and medieval times showed commonness and universality, jewelry in modern time expressed individuality. Although the meaning of jewelry changed progressively by interacting with the external environment, jewelry has always roused sense and symbolism from our hearts and has acted as a means to express ideas and emotions of human beings.