• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.345-351
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• 2006

습지나 얕은 바다에 존재하는 중금속의 분포를 모델링하는 것은 그 곳의 생태계를 보존하기 위해 꼭 필요한 일이다. 본 연구에서는 GIS(Geographic Information System) 기법 및 위성영상, 실제 대상지역 측량자료를 이용하여 베트남의 동남쪽에 있는 메콩강 삼각주 지역의 중금속 분포를 예측하는 기법을 제안하였다. 이를 위해 중금속의 분포에 영향을 미치는 공간적 요소(Spatial factor)와 구조적 요소(Structural factor)를 통계적으로 처리함으로써 대상지역에 대한 As(arsenic) 오염도를 예측하였다. 또한 중금속 오염되었다고 평가된 지역을 위성영상을 이용하여 표현함으로써 본 연구의 결과를 시각적으로 제시하였다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.1
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• pp.9-14
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• 2008

This paper presents an observer design methodology for a special class of multi input multi output(MIMO) nonlinear systems. First, we characterize the class of MIMO nonlinear systems with a triangular structure. Also, the observability matrices that plays an important role in proving the convergence of the proposed observer are generalized to MIMO systems. By using the generalized observability matrices, it is shown that under the boundedness conditions of system state and input, the proposed observer guarantees the local exponential convergence to zero of the estimation error.

• Proceedings of the Korean Society for Information Management Conference
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• 2005.08a
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• pp.357-364
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• 2005

저자동시인용 자료에 대한 분석 도구로 삼각매개중심성 (triangle betweenness centrality; TBC) 척도를 비롯하여 네 가지 새로운 척도를 제안하고 정보학 분야의 지적 구조 분석에 적용해보았다. 제안한 척도는 사회네트워크 분석 분야에서 사용되고 있는 여러 중심성 척도를 참고하여 동시인용 데이터에 적합하도륵 고안되었다. 검증을 위해서 이은숙, 정영미(2002)의 연구에서 수집한 1990년부터2000년까지 11년간 Journal of America Society for Information Science에 인용된 주요 저자50명의 동시인용 네트워크를 여러 중심성 척도를 사용해서 분석하였다. 전통적인 분석 도구인 다차원척도법이나 군집분석과 달리 중심성 척도를 통해서는 저작물에 반영된 개별 저자의 입지와 영향력에 대한 구체적인 분석이 가능하였다. 특히 삼각매개중심성 척도는 측정 범위의 조절이 자유로와서 지역적 중심성과 전역적 중심성을 모두 파악할 수 있는 것으로 나타났다.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1998.10a
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• pp.849-853
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• 1998

라인 해석법(Method of Line), MOL과 파수 영역 해석법(Space Domain Approach), SDA를 결합한 공간-파수 영역 해석법(SSDA)를 이용하여 MIC/MMIC 회로에서 임의 입체 구조를 갖는 공진기를 해석한다. SSDA는 상대 수렴(relative convergence)특성을 갖지 않으며, 반 해석적 (semianalytical )특성으로 수치적 효율이 높다. 경계치 문제로부터 씨스팀 행렬방정식 형태로 유도된그린 함수에 갤러킨법을 적용한다. 삼각, 사각 및 불연속 구조를 갖는 스트립 패치의 폭, 위치와 기판의 두께 변화에 따른 공진 주파수를 계산하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.2 no.4
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• pp.209-216
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• 1998

본 논문에서는 부채꼴형 Mindlin 평판의 엄밀한 휨진동해를 제시하였다. 진동변위의 두 가지 적합 함수식, 즉 대수삼각다항식과 Mindlin 모서리함수를 Ritz방법에 적용하였다. 모서리함수는 부채꼴형 평판의 둔각 정점부에 존재하는 모멘트와 전단력의 특이도를 동시에 고려하고 있다. 이러한 모서리함수는 진동수의 수렴속도를 가속화한다. 본 연구에서는 부채꼴형 각도의 범위와 두께 비에 따른 엄밀한 진동수 및 수직진동 변위의 전형적인 등고선을 제시하였다.

• Korean Journal of Optics and Photonics
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• v.16 no.3
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• pp.261-265
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• 2005

The large and polarization-independent photonic bandgap (PBG) is very useful to the application to various optical devices. Until present, it has been known that the PBG for a triangular lattice remains the largest both in the E- and H-polarized modes. However, we proposed a new structure with a larger polarization-independent PBG, by analyzing and systemizing the PBG opening trends as the structural changes. This optimal structure for maximum bandgap has more increased gap-midgap ratio $(\Delta\omega/\omega)$ of about $30\%$ than the triangular lattice.

• Journal of Korean Society of Steel Construction
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• v.24 no.3
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• pp.267-278
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• 2012

In general, the H-shaped steel ribs or triangular lattice girders have been mostly used in constructing tunnels through the NATM construction method. The H-shaped steel rib has higher flexural and axial strength than the triangular lattice girder, but many unexpected gaps can occur in the concrete lining system after shotcreting if the H-shaped steel rib is used as the support system. To achieve better shotcreting quality, the triangular lattice girder was developed. However, in general, the triangle lattice girder has low flexural and axial strength. Likewise, the triangular lattice girder, which has circular sectional members, has so many fractures from welded points at the joints between the members. Finally, the new type of tetragonal lattice girder was developed to overcome those problems. In this study, the structural performance of the tetragonal lattice girders was evaluated through analytical and experimental studies. In the analytical studies, the four-point bending analysis, the traditional evaluation method to determine the flexural strength of the lattice girder, was performed. Moreover, the linear-elastic analysis and stability analysis of the arch structure made by the lattice girders were performed to measure structural performance. Experiments were likewise performed to compare the structural performances of the tetragonal girder with traditional triangular lattice girders.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.19-27
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• 2023

This paper is aimed at exploring a multi-racial, multi-ethnic, and multi-cultural trianglulation of Black, White, and Korean American race relations connected to a large-scale disturbance in the 1992 Los Angeles riots. The second generation Korean American Steph Cha's Your House Will Pay (2019) focuses on a social portrait of the racially marginalized beings as Korean immigrant merchants and African American native consumers. This family saga explores issues resulting from racial hierarchy, racialized stereotypes, and historical marginalization in the internalized sociometry of race and class inequality. This work grapples with issues involved in a sociocultural web of racial triangulation under the white dominant structure, and ensuing intergroup conflicts of social minorities in the economic geography of urban space. It opens up civil discussions for transracial, transethnic, and transcultural interactions and coexistence. It ultimately leads to extending young people's minds for a deep understanding of the socioecomonic landscape of racial matrix, and enhancing the cultural literacy for a better awareness of social empathy and the communal respect of life.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.1
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• pp.35-44
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• 2009

This paper describes an application of domain decomposition method for parallel finite element analysis which is required to large scale 3D structural analysis. A parallel finite element method system which adopts a domain decomposition method is developed. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Delaunay triangulation method is introduced as a basic tool for element generation. Domain decomposition method using automatic mesh generation system holds great benefits for 3D analyses. Aa parallel numerical algorithm for the finite element analyses, domain decomposition method was combined with an iterative solver, i.e. the conjugate gradient(CG) method where a whole analysis domain is fictitiously divided into a number of subdomains without overlapping. Practical performance of the present system are demonstrated through several examples.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.355-360
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• 2012

In this paper, an stepped-impedance low pass filter(SI-LPF) of triangular-patch type is proposed. A SI-LPF designed according to the standard SI-LPF design procedure is folded as a right angled triangle. The figure of merits of this structure are the adjustabilities of the cut off frequency, the stopband and the attenuation pole frequency of the proposed LPF by varying the resultant slots after folding the SI-LPF compactly for miniaturization. The size of the fabricated LPF is $13.75mm{\times}6.875mm$, which is 24.4 % reduced one compared to that of the conventional SI-LPF. The measured results of the LPF show return loss of less than -10 dB at passband, insertion loss of less than -10 dB at stopband and wide stopband from 3.5 GHz to 10 GHz (about $3f_c$).