• 제목/요약/키워드: 3D Topography

검색결과 242건 처리시간 0.027초

Evaluation of the Tribological Parameters of Three-dimensional Surface Topography with Various Property

  • Uchidate, M.;Shimizu, T.;Iwabuchi, A.
    • 한국윤활학회:학술대회논문집
    • /
    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
    • /
    • pp.249-250
    • /
    • 2002
  • In this paper, the relationship among the 3-D surface topography parameters are studied. Several surface topography parameters that are important in tribology are calculated against various surface topography data. 3-D surface data with desired properties are generated by using the non-causal 2-D auto-regressive (AR) model. The non-causal 2-D AR model is a random 3-D surface topography model that can generate 3-D surface topography data with specified parameters.

  • PDF

측만증 환자에서 3차원 체표면 영상분석과 Cobb 각의 상관관계 (Correlation of the 3D-Surface Topography and Cobb's Angle in Scoliotic Patient's)

  • 최은정;김태열
    • 대한임상전기생리학회지
    • /
    • 제3권1호
    • /
    • pp.61-70
    • /
    • 2005
  • The purpose of study correlation between 3D-surface topography and Cobb angle in scoliotic patients. It would be recognizing possibility of clinical application with 3D-surface topography with scoliosis assessment and correlation analysis of obtained Cobb angle through measured results of surface topography and took X-ray of subjects with scoliosis, which used to 3D-surface topography of laser scan method. A scoliosis subjects 16(males 4, females 12) agreed for study's purport volunteer our study that diagnose the scoliosis through 3D-surface topography and X-ray. The results were as follow: It was shown that the relation of Cobb angle of scoliosis and itemized 3D-surface topography measurement in horizontal view(p<0.01). top difference of cervicothoracic and lumbar in anterior-posterior view(p<0.05), the top difference of thoracic, thoracolumbar(p<0.01). These results suggest that an itemized 3D-surface topography measurement was highly correlated with Cobb angle. It would be a useful diagnosis method and assessment of physical therapy plan.

  • PDF

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

  • 유원재;김도훈;안재웅;강영준;노형민
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2002년도 춘계학술대회 논문집
    • /
    • pp.199-202
    • /
    • 2002
  • Moire topography method is a well-known non-contacting 3-D measurement method. Recently, 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 paper, using different N-bucket algorithm method of digital projection moire topography is tested to measuring object with the 2$\pi$-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding measurement errors that decreased more by using the flour-three step algorithm method than the same step in the phase shifting of different pitchs.

  • PDF

보간 알고리즘 비교와 폴리곤 테크닉에 기초한 3차원 EEG 맵핑 (A 3-dimensional EEG topography based on the polygon technique)

  • 한이범;이용희;김선일
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 1998년도 하계종합학술대회논문집
    • /
    • pp.581-584
    • /
    • 1998
  • To obtain 3-D topography of EEG records, we propose a new method based on the polygon mapping technique. The method has the low complexity to calculate the interpolation of the EEG records on the scalp and maintains the high resolution topography because the polygon technique performs the interpolation at the only vertexes of each polygon. We implemented the topographic system with 3D barycentric, 3D polynomial and spherical spline algorithms in a personal computer.

  • PDF

3-D Reconstruction of Human Face Using the Derivative Moiré Topography

  • Bae, Yoon Jae;Ha, Byeong Wan;Park, Ji An;Cho, Choon Sik
    • Journal of the Optical Society of Korea
    • /
    • 제18권5호
    • /
    • pp.500-506
    • /
    • 2014
  • A new 3-D reconstruction algorithm for the human face is proposed using the derivative Moir$\acute{e}$ topography which ensures fast and robust reconstruction even for rough surfaces. The Moir$\acute{e}$ interference fringe pattern is initially obtained through the projection Moir$\acute{e}$ topography based on phase shifting, and then differentiated to provide a full unwrapped phase map for a human face. $2{\pi}$ ambiguity, which has been a chronically unsolved problem with Moir$\acute{e}$ topography, is successfully surmounted by differentiating the Moir$\acute{e}$ fringe patterns both in x- and y-directions when the object is located in the x-y plane. A real human face is used for verifying the proposed derivative Moir$\acute{e}$ topography. A human face of 4 different phase-shifted images taken in the fixed plane is almost fully reconstructed in 3-D format in 0.1 mm lateral resolution.

인체형상 측정을 위한 가상격자 영사식 무아레 방법에 관한 연구 (A Study on the Virtual Grating Projection Moire Topography for the Shape Measurement of Human Face)

  • 유원재;최정표;안중근;강영준
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2001년도 춘계학술대회 논문집
    • /
    • pp.49-52
    • /
    • 2001
  • Moire topography method is a well-known non-contacting 3-D measurement method. Recently, 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 projection moire topogrphy is very attractive because of it s high measuring speed and high sensitivity. In this paper, using two-wavelength method of projection moire topography tested to measuring object with the $2\pi$-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding absolute fringe orders, so that the $2\pi$-ambiguity problem can be effectively overcome so as to treat large step discontinuities in measured objects.

  • PDF

인체흉상 합성을 위한 3차원 형상 측정에 관한 연구 (A study on 3-D shape measurement for the composition of human bust)

  • 안중근;강영준;최정표;유원재
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1997년도 추계학술대회 논문집
    • /
    • pp.220-223
    • /
    • 1997
  • Moire topography method is a well-known non-contacting 3-D measuement method. Recently, 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 projection moire topography is very attractive because of it's high measuring speed and high sensitivity. In this paper, using two-wavelength method of projection moire topography tested to measuring object with the 2x-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding absolute fringe orders, so that the 2x-ambiguity problem can be effectively overcome so as to treat large step discontinuities in measured objects.

  • PDF

디지털 영사식 무아레를 이용한 3차원 형상 측정과 응용에 관한 연구( I ) (A Study on 3-D Shape Measurement and Application by using Digital Projection $Moir\acute{e}$ ( I ))

  • 유원재;노형민;이동환;강영준
    • 한국정밀공학회지
    • /
    • 제22권7호
    • /
    • pp.88-93
    • /
    • 2005
  • $Moir\acute{e}$ topography method is a well-known non-contacting 3-D measurement method. Recently, the automatic 3-D measurement by $Moir\acute{e}$ topography has been required, since the method was frequently applied to the engineering and medical fields. The 3-D measurement using projection $Moir\acute{e}$ topography is very attractive because of its high measuring speed and high sensitivity. In this paper, using two-wavelength method of projection $Moir\acute{e}$ topography was tested to measuring object with $2\pi-ambiguity$ problems. The experimental results prove that the proposed scheme is capable of finding absolute fringe orders, so that the $2\pi-ambiguity$ problems can be effectively overcome so as to treat large step discontinuities in measured objects.

Underwater 3D Reconstruction for Underwater Construction Robot Based on 2D Multibeam Imaging Sonar

  • Song, Young-eun;Choi, Seung-Joon
    • 한국해양공학회지
    • /
    • 제30권3호
    • /
    • pp.227-233
    • /
    • 2016
  • This paper presents an underwater structure 3D reconstruction method using a 2D multibeam imaging sonar. Compared with other underwater environmental recognition sensors, the 2D multibeam imaging sonar offers high resolution images in water with a high turbidity level by showing the reflection intensity data in real-time. With such advantages, almost all underwater applications, including ROVs, have applied this 2D multibeam imaging sonar. However, the elevation data are missing in sonar images, which causes difficulties with correctly understanding the underwater topography. To solve this problem, this paper concentrates on the physical relationship between the sonar image and the scene topography to find the elevation information. First, the modeling of the sonar reflection intensity data is studied using the distances and angles of the sonar beams and underwater objects. Second, the elevation data are determined based on parameters like the reflection intensity and shadow length. Then, the elevation information is applied to the 3D underwater reconstruction. This paper evaluates the presented real-time 3D reconstruction method using real underwater environments. Experimental results are shown to appraise the performance of the method. Additionally, with the utilization of ROVs, the contour and texture image mapping results from the obtained 3D reconstruction results are presented as applications.

측만증 환자의 3차원 체표면 영상분석 (Analysis of the 3D-Surface Topography in Scoliosis)

  • 최은정;김태열;김용남;최은영;최현석
    • 대한임상전기생리학회지
    • /
    • 제2권3호
    • /
    • pp.51-64
    • /
    • 2004
  • This study understood measured items of significantly difference through the surface topographical comparison of dorsal trunk's surface between normal and scoliosis subjects. 300 subjects for this study were participated (middle, high school and college students). Normal 28(males 12, females 16) and scoliosis subjects 16(males 4, females 12) were chosen by assessment tools (physical examination, 3D-surface topography) among subjects at Dongshin University Oriental Hospital. The results were as follow: 1. It was shown that the significantly difference was observed by distance of peak to curve with scoliosis between two groups(p<0.001). 2. It was shown that top difference of between groups in anterior-posterior view was the significantly difference at cervicothoracic, thoracic, thoracolumbar and dorsal part of lumbar(p<0.001). These results suggest that method to use 3D-surface topography measurement would be useful diagnosis method and clinical use of physical therapy.

  • PDF