• Title/Summary/Keyword: 3D Topography

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A Study on Projective Calibration for Arbitrary Display Surface using Digital Moire Method. (Digital Moire를 이용한 임의의 영사면에 대한 투영보정에 관한 연구)

  • 유원재;김도훈;강영준;백성훈
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.292-295
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    • 2003
  • Moire topography method is a well-known non-contacting 3-D measurement method. the automatic 3-D measurement by moire topography has been required since the method was frequently applied to the engineering and medical fields. 3-D measurement using digital projection moire topography is very attractive because of its high measuring speed and high sensitivity. In this study, digital two-wavelength phase shilling moire is applied to the entertainment fields. recently. as promoting the growth of the VR-Game, display devices which attract public attention such as HMD or Projector are being appeared in order to deliver effectively the absorption sense. this study realized the Auto-calibrating system for arbitrary display surface using digital moire method which satisfied the shape measurement of display surface and the request of FOV(Field of View) output. also when large screen wasn't prepared, this auto-calibrating system was applied to enjoy games or movies at home with a projector and walls

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A Study on the Calibration of Shape Measurement System Using Digital moire (Digital moire 형상측정 시스템의 보정에 관한 연구)

  • 김도훈;유원재;박낙규;강영준
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.04a
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    • pp.255-259
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    • 2003
  • Moire topography method isa well-known non-contacting 3-D measurement method as afast non-contact test for three-dimension shape measuring method. Recently, it's important to study the automatic three-dimension measurement by moire topography because it is frequently applied to the reverse engineering , the medical , the entertainment fields. Three-dimension measurement using projection of moire topography is very attractive because of its high measuring speed and high sensitivity. In this paper, the classical moire method is computerized-so called digital moire when a virtual grating pattern is projected on a surface, the captured image by the CCD camera has three-dimension information of the objects. The moire image can be obtained through a simple image processing and a reference grating pattern. and it provides similar results without physical grating pattern. digital projection moire topography turn out to be very effective for the three-dimension measurement of objects. Using different N-bucket algorithm method of digital projection moire topography is tested to measuring object with the 2-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding measurement errors that decreased more by using the four-three step algorithm method instead of the same step in the phase shifting of different pitch.

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3D Wear Analysis of Valve Assemblies by Using the Machine Vision (머신비전을 이용한 밸브어셈블리의 3차원 마멸특성 분석)

  • Park Chang-Woo;Chung Sung-Chong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.5 s.248
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    • pp.496-504
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    • 2006
  • Wear of engine valves and seat inserts is a major factor affecting engine performance. In order to improve quality and life of valve assemblies, wear mechanism and 3-D surface topography should be analyzed according to operating conditions of the engine. After developing an engine simulator that generates valve speed up to 90Hz and temperature up to $900^{\circ}C$ as well as controls test load, wear experiments have been conducted for two different engine speeds as 10Hz and 25Hz. In order to observe the wear characteristics and monitor surface conditions of the valve assemblies, a cost-effective 3-D wear analysis system based on the shape from focus(SFF) and machine vision has been fabricated in this paper. 3-D surface topography of the valve assemblies has been analyzed to understand the wear behavior according to operating conditions of the engine. Consequently, wear volume of the valve assemblies is quantized by using the developed 3-D wear analysis system.

Surface Structure and X-ray Topography of $NdAl_3(BO_3)_4$ Single Crystals Grown from High Temperature Solution of $BaO-B_2O_3-Nd_2O_3-Al_2O_3$ System ($BaO-B_2O_3-Nd_2O_3-Al_2O_3$계 고온 용액으로부터 성장된 $NdAl_3(BO_3)_4$ 단결정의 표면구조와 X-선 Topography)

  • 정선태;강진기;김정환;정수진
    • Journal of the Korean Ceramic Society
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    • v.31 no.3
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    • pp.249-256
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    • 1994
  • By surface structure and X-ray topographic observation, growth mechanism of NAB single crystal grown by TSSG technique using a BaB4O7 flux was studied. Surface structure of grown crystals were investigated by optical microscope. Growth history and crystal defects included within grown crystal were investigated using X-ray topography. The {001} faces were grown by 2-D nucleation growth. As decreasing cooling rate, growth mechanism of {111} and {11} was changed from 2-D nucleation growth to the growth by screw dislocation. Only surface striations developed parallel to a-axis were observed on {010} faces. Growth sector of NAB crystals were divided into {001}, {111}, {010}, {021}, {11}. The inclusion which was usually trapped between {001} faces was investigated.

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Three dimensional visualization of seafloor topography for the application of integrated navigation system (통합항법시스템에 적용하기 위한 3차원 해저지형의 시각화)

  • Bae, Mun-Ki;Shin, Hyeong-Il;Lee, Dae-Jae;Kang, Il-Kwon;Lee, Yoo-Won;Kim, Kwang-Sik
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.42 no.2
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    • pp.104-110
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    • 2006
  • The 3D visualization of seafloor topography(ST) was realized to discuss the effective use by the 3D visualization of ST on the integrated navigation system(INS) for fishing boat. The software was to actually display the 3D visualization of ST using triangular irregular network, helical hyperspatial codes and stereo projection. The INS for fishing boat which applied the 3D visualization of ST will be utilized for safety voyage and the effective fishing work on the fishing ground.

Effects of 3D Topography on Magnetotelluric Responses (MT 탐사의 3차원 지형효과)

  • Nam, Myung-Jin;Kim, Hee-Joon;Song, Yoon-Ho;Lee, Tae-Jong;Suh, Jung-Hee
    • Geophysics and Geophysical Exploration
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    • v.10 no.4
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    • pp.275-284
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    • 2007
  • For precise interpretation of magnetotelluric (MT) data distorted by irregular surface terrain, topography effects are investigated by computing apparent resistivities, phases, tippers and induction vectors for a three-dimensional (3D) hill-and-valley model. To compute MT responses for the 3D surface topography model, we use a 3D MT modeling algorithm based on an edge finite-element method which is free from vector parasites. Distortions on the apparent resistivity and phase are mainly caused by distorted currents that flow along surface topography. The distribution of tipper amplitudes over both hill and valley are the same, while the tipper points toward the center of hill and the base of the valley. The real part of induction vector also points in the same direction as that of tipper, while the imaginary part in the opposite direction.

Fundamental Morphological Consideration for the 3-D Shape Analysis of the Middle-aged Women's Breast (중년 여성의 3차원 유방 형상 분석을 위한 방법론 연구)

  • 이현영;홍경희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.26 no.5
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    • pp.703-714
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    • 2002
  • This paper proposed the basic consideration for the reliable 3-D measurement and analysis of middle-aged women's breast using 3-D phase-shifting moire topography. The surface borderline of the breast based on the anatomical structure on the skin was suggested. Various breast dimensions that can be measured using 3-D measurement system and their measuring methods were discussed. Tips for the measurement of sagged breast were also proposed. It is expected that these basic considerations contribute to draw attention to the reliable measurement of women's breast and provide a kind of tools for the standardization of 3-D shape measurement of breast.

Advances in Imaging of Subsurface Archaeology using GPR

  • Dean, Goodman;Yasushi, Nishimur;Kent, Schneider;Salvadore, Piro;Hiromichi, Hongo;Noriaki, Higashi
    • Journal of the Korean Geophysical Society
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    • v.7 no.3
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    • pp.161-170
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    • 2004
  • Examples of GPR survey results at a variety of archaeological sites are presented. Several new analyses which include static corrections for the tilt of the GPR antenna are shown for imaging of burial mounds with significant topography. Example archaeological site plans developed from GPR remote sensing of Roman and Japanese sites are given. The first completely automated GPR survey, using only Global Positioning Satellite navigation to create 3D data volumes, is employed for a site in Louisiana to detect lost graves of the Choctaw Indian Tribe.

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A Study on the 3-D Digital Modelling of the Sea Bottom Topography (3차원 해저지형 수치모델에 관한 연구)

  • 양승윤;김정훈;김병준;김경섭
    • Journal of the Korea Institute of Military Science and Technology
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    • v.5 no.3
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    • pp.33-44
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    • 2002
  • In this study, 3-dimensional virtual visualization was performed for a rapid and accurate analysis of sea bottom topography. The visualization was done through the extracted data using the developed program and the generated data using the gridding method. The data extraction program was developed with AutoLISP programming language and this program was able to extract the needed sample bathymetry data from the electronic sea chart systematically as well as effectively The gridded bathymetry data were generated by the interpolation or extrapolation method from the spatially-irregular sample data. As the result of realization for the 3-dimensional virtual visualization, it was shown a proper feasibility in the analysis of the sea bottom topography to determine the route of submarine cable burial.

A Study on the 3-D Digital Modelling of the Sea Bottom Topography (3차원 해저지형 수치모델에 관한 연구)

  • 양승윤;김정훈;김병준;김경섭
    • Journal of the Korea Institute of Military Science and Technology
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    • v.5 no.2
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    • pp.50-61
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    • 2002
  • In this study, 3-dimensional virtual visualization was performed for a rapid and accurate analysis of sea bottom topography, The visualization was done through the extracted data using the developed program and the generated data using the gridding method. The data extraction program was developed with AutoLISP programming language and this program was able to extract the needed sample bathymetry data from the electronic sea chart systematically as well as effectively. The gridded bathymetry data were generated by the interpolation or extrapolation method from the spatially-irregular sample data. As the result of realization for the 3-dimensional virtual visualization, it was shown a proper feasibility in the analysis of the sea bottom topography to determine the route of submarine cable burial.