• 한국농공학회논문집
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• 제47권5호
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• pp.3-13
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• 2005

The present study examined the 3 dimensional space distribution characteristics of sea water intrusion using data available from previous observations. For this study, we used 3D FEMWATER, which is a 3 dimensional finite element model. The target area was around Daechang-ri, Gimje-si, Jeollabuk-do. The area is relatively easy to formulate a conceptual model and has observation wells in operation for surveying sea water intrusion. Considering the uncertainty of numerical simulation, we analyzed sensitivity to hydraulic conductivity, which has a relatively higher effect. According to the result of the analysis, the variation of TDS concentration had an error range of $-1,336{\~}+107 mg/{\iota}$. Taking note that the survey data from observation wells were collected when the boundary between fresh water and sea water in the aquifer was in equilibrium, we set the range of time for numerical simulation and estimated the spatial distribution of TDS concentration as the range of sea water intrusion. According to the result of estimation, the spatial distribution of TDS concentration calculated when 1,440 days were simulated was taken as the range of sea water intrusion. Using the result of calculation, we can draw not only vertical views for a certain section but also horizontal views of different depth. These views will be greatly helpful in understanding the spatial distribution of the range of sea water intrusion. In addition, the result of this study can be used rationally in proposing an optimal quantity of water pumping through investigating the moving route of sea water intrusion over time in order to prevent excessive water pumping and to maintain an optimal number of water pumping wells per interval.

• 한국정보통신학회논문지
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• 제10권5호
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• pp.928-933
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• 2006

이 논문은 사용자가 2D/3D 공간 데이터를 안전하게 하면서 속성 정보를 공급하는 방식을 활용하여 효과적으로 작동할 수 있는 2D/3D 맵 네비게이션 체계를 구축하는데 목적을 두었다. 이 시스템은 사용자가 검색하는 위치를 2D 또는 3D 방식으로 다양하게 전의 할 수 있도록 지원해 준다. 또한 이 시스템은 고해상도의 조형물 전의가 가능하도록 해줄 뿐만 아니라 기존의 2D/3D에 비해 명칭, 전화 번호, 기타 관련된 정보를 효과적으로 지원해주는 2D/3D 공간 데이터 베이스 기술을 적용하였으며 통합된 2D/3D 공간데이터 베이스 구조를 활용함으로써 다양한 인터페이스의 개발 적용과 더불어 개발 생산성을 향상시켰다.

• 대한토목학회논문집
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• 제31권2A호
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• pp.121-127
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• 2011

콘크리트 내부에 존재하는 공극(void)의 공간적 분포는 콘크리트의 역학적, 물리적 거동에 큰 영향을 미친다. 따라서 콘크리트 재료 물성의 파악과 건정성 평가를 위해 내부에 존재하는 공극의 분포 상태를 파악하는 것은 매우 중요하다. 콘크리트에는 육안으로 보이는 재료 표면의 공극 이외에도 내부 공극이 존재한다. 본 연구에서는 경량골재 콘크리트의 공극 분포를 파악하기 위하여 micro CT(X-ray microtomography)를 활용하여 생성된 3차원 콘크리트 디지털 시편을 사용하였다. 흑백처리된 단면 이미지를 중첩하여 공극을 묘사할 수 있는 3차원 시편을 생성하였다. 공극의 분포 상태를 확률적으로 묘사하기 위하여 확률 분포 함수 two-point correlation function과 lineal-path function으로 분석하였다. 또한, 이미지 분석을 통해서 콘크리트 시편의 공극의 밀도 분포를 파악하였다. 콘크리트 내부에 있는 개별 경량 골재의 공극도 이미지 처리와 확률 분포함수를 사용하여 분석하였다. Micro CT와 3차원 이미지 분석 방법을 통하여 콘크리트 내부에 존재하는 공극의 분포 상태를 효과적으로 파악할 수 있음을 확인하였다.

• Spatial Information Research
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• 제19권3호
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• pp.33-42
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• 2011

항공사진을 이용한 3차원공간정보구축 방법이 대두됨에 따라, 효율적인 작업 방법과 활용 방안에 대한 논의가 지속되어져 오고 있다. Pictometry를 활용한 3차원공간정보구축에는 경사사진과 수직사진이 동시에 획득되어지므로 기존 사진측량이론과 상이한 다각촬영(Multi-Looking)카메라의 작업방법에 따라 3차원 위치결정을 수행한다. 이때 지상기준점의 관측수량 및 배치는 최종성과물인 정밀정사영상(True Orthoimage)의 절대정확도에 영향을 미치게 된다. 따라서 본 연구에서는 지상기준점 수량 및 배치에 따른 정밀정사영상의 정확도 평가를 수행하고 허용오차범위를 만족시키는 지상기준점 선점 기준을 확인하였으며 다각촬영카메라의 3차원위치결정 작업방법에서 효율적인 지상기준점 관측 방안을 제시하였다.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2004년도 Proceedings of 2004 Korea-Japan Joint Seminar on Particle Image Velocimetry
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• pp.33-40
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• 2004

A 4D-PTV system was constructed. The measurement system consists of three high-speed high-definition cameras(1k x 1k, 2000fps), Nd-Yag laser(2000Hz) and a host computer. The GA-3D-PTV algorithm was used for completing the measurement system. The 4D-PTV is capable of probing the spatial distribution of velocity vectors of the flow field overcoming the temporal resolution of the characteristic turbulence length scales of the measured flow fields. A horizontal impinged jet flow (H/D=7) was measured. The Reynolds number is about 33,000. Spatial temporal evolution of the jet flow was examined and physical properties such as spatial distributions of vorticity and turbulent kinetic energy were obtained with the constructed.

• 한국대기환경학회지
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• 제13권6호
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• pp.463-474
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• 1997

Metallic elements in dustfall have been known as notable air pollutants directly or indirectly influencing human health and wealth. The first aim of this study was to obtain precise spatial distribution patterns of 5 elements (Pb, Zn, K, Cr, and Al) in dustfall around Suwon area. To predict isometric lines of metal fluxes deposited on unsupervised random sites, the study has applied both spatial statistics as a receptor model and a GIS (geographic information system). Total of 31 sampling sites were selected in the study area (roughly 3 by 3 km grid basis) and dustfall samples were then collected monthly basis by the British deposit gauges from Dec., 1995 to Nov., 1996. The metallic elements in the dustfall were then analyzed by an atomic absorption spectrometer (AAS). On the other hand, a base map overlapped by 7 layers was constructed by using the AutoCAD R13 and ARC/INFO 3.4D. Four different spatial interpolation and expolation techniques such as IDW (inverse distance weighted averaging), TIN (triangulated irregular network), polynomial regression, and kriging technique were examined to compare spatial distribution patterns. Each pattern obtained by each technique was substantally different as varing pollutant types, land of use types, and topological conditions, etc. Thus, our study focused intensively on uncertainty analysis based on a concept of the jackknife and the sum of error distance. It was found that a kriging technique was the best applicalbe in this study area.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.490-495
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• 2009

An approach to 3D visualization of multiple sound sources has been developed with the application of a moving array technique. Frequency-domain beamforming algorithm is used to generate a beam power map and the sound source is modeled as a point source. When a conventional delay and sum beamformer is used, it is considered that 2D distribution of sensors leads to have deficiency in spatial resolution along a measurement distance. The goal of moving an array in this study is to form 3D array aperture surrounding multiple sound sources so that the improved spatial resolution in a virtual space can be expected. Numerical simulation was made to examine source localization capabilities of various shapes of array. The 3D beam power maps of hemispherical and spherical distribution are found to have very sharp resolution. For experiments, two sound sources were placed in the middle of defined virtual space and arc-shaped line array was rotated around the sources. It is observed that spherical array show the most accurate determination of multiple sources' positions.

• 한국소음진동공학회논문집
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• 제19권9호
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• pp.907-914
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• 2009

An approach to 3D visualization of multiple sound sources has been developed with the application of a moving array technique. Frequency domain beamforming algorithm is used to generate a beam power map and the sound source is modeled as a point source. When a conventional delay and sum beamformer is used, it is considered that 2D distribution of sensors leads to have deficiency in spatial resolution along a measurement distance. The goal of moving an array in this study is to form 3D array aperture surrounding multiple sound sources so that the improved spatial resolution in a virtual space can be expected. Numerical simulation was made to examine source localization capabilities of various shapes of array. The 3D beam power maps of hemispherical and spherical distribution are found to have very sharp resolution. For experiments, several sound sources were placed in the middle of defined virtual space and arc-shaped line array was rotated around the sources. It is observed that spherical array shows the most accurate determination of multiple sources' positions.

• 지구물리와물리탐사
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• 제17권2호
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• pp.49-57
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• 2014

금산지역 항공 자력자료에 대하여 2차원 수치모델링 및 역산조합으로 구한 사전정보를 이용하는 3차원 자력역산을 수행하고 지질정보와 대비하여 함우라늄 층과 여타 옥천누층군 단위 암상에 대응하는 자기감수율의 공간적 분포특성을 고찰하였다. 체적당 자기감수율 분포 및 수평 슬라이스 시각화를 통해 흑색셰일형 함우라늄층인 흑색 점판암과 대응하는 자력이상 값은 우라늄 광화대와 전체적으로 양호한 상관관계를 보여주었다. 회색 혼펠스층 우라늄 광화대의 간접 지시자인 마전리층 및 암회색 점판암층 역시 석영반암 경계에서부터 동남쪽으로 발달하는 자력선구조 특성을 잘 보여주었다. 인접한 강한 자기감수율 이상을 보여주는 암회색 점판암과 분리하여 인지 가능한 함우라늄 흑색 점판암층의 최대 깊이는 고도 306m 기준으로 약 150m 안팎으로 판단하였다. 한편, 흑색 점판암층 남쪽의 마전리층은 다소 높은 자기감수율 분포를 보여주나 자기감수율의 공간적 변동이 심한 특징을 보이며 관입암인 주라기 화강암은 낮은 자기감수율 특성을 보여주는 반면, 백악기 화강암은 상대적으로 높은 자기감수율 특성을 나타내었다.

• Wind and Structures
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• 제5권5호
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• pp.441-462
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• 2002

This paper presents a practical numerical method to determine both the spatial and temporal distribution of driving rain on buildings. It is based on an existing numerical simulation technique and uses the building geometry and climatic data at the building site as input. The method is applied to determine the 3D spatial and temporal distribution of wind-driven rain on the facade a low-rise building of complex geometry. Distinct wetting patterns are found. The important causes giving rise to these particular patterns are identified : (1) sweeping of raindrops towards vertical building edges, (2) sweeping of raindrops towards top edges, (3) shelter effect by various roof overhang configurations. The comparison of the numerical results with full-scale measurements in both space and time for a number of on site recorded rain events shows the numerical method to yield accurate results.