• 제목/요약/키워드: curvature measurement method

검색결과 100건 처리시간 0.03초

영상처리에 의한 경량기포 콘크리트 블록의 치수측정 및 불량경사 알고리즘 개발 (Development of Size Measurement and Inspection Algorithm for Autoclaves Lightweight Concrete Block by Image Processing)

  • 김성훈;허경무
    • 전자공학회논문지CI
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    • 제40권4호
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    • pp.206-213
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    • 2003
  • 본 논문에서는 고성능의 하드웨어 장비가 아닌 일반적으로 사용되는 개인용 컴퓨터와 CCD 카메라를 이용하여 자동으로 경량기포 콘크리트(autoclaved lightweight concrete) 블록간의 상하 경사도, 두께의 불균일성, 그리고 불량 여부를 판별할 수 있는 알고리즘을 제안하였다. 제안한 치수측정 및 불량검사 자동화 알고리즘은 실제 작업환경을 고려하여 일반적인 조명조건에서의 전처리과정과 작업공정내의 피사체의 진동을 고려한 단위길이 결정방법, 카메라의 곡률보정에 의한 치수오차 보정 방법 등을 적용하였으며, 실제공정에서의 실험 결과를 통해 블록군의 계측에 있어서 0.8초 이내에 측정오차 1%이내의 데이터를 산출해 냄으로서 제안한 불량검사 자동화시스템의 신뢰성을 검증할 수 있었다.

3차원 인체의 곡률분포를 이용한 패턴 전개 (Pattern Development using the Curvature Plot of 3D Human Scan Data)

  • 정연희;홍경희
    • 한국의류학회지
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    • 제32권9호
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    • pp.1478-1486
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    • 2008
  • The human body composed of concave and convex curvatures, and the current 3D scanning technology which involves inherent measurement errors make it difficult to extract distinct curvature plot directly. In this study, a method of extracting the clear curvature plot and its application to the cycling pants design were proposed. We have developed the ergonomic pattern from the 3D human body reflecting cycling posture. For the ergonomic design line on the 3D human body, the 3D information on the lower part of four male bodies with flexed posture was analyzed. The 3D scan data of four subjects were obtained using Cyberware. As results, the iteration of the tessellated shell was executed 100 times to obtain optimized curvature plots of the muscles on the body surface, and the boundaries of the curvature plots were applied to the design lines. Maximum(Max-pattern) and mean curvature plots(Mean-pattern) were adopted in the design line of the cycling pants, and performance of those lines was compared with that of conventional princess line(Con-pattern). The average error of total area and length in the 2D pattern developed from the 3D flexed body surface in this study were very minimal($4.58cm^2$(0.19%) and 0.15mm(0.46%)), which was within the range of tolerable limits in clothing production. The pattern obtained from the flexed body reflecting cycling posture already included the contraction and extension of the cycling skin, so that the extra ease for movement and good fit was not need to be considered.

하중 게재시 정지상태 및 이송속도에 따른 테이블 처짐에 관한 연구 (A Study on the Table Deflection by Stop State and Move Speed at Loaded Load)

  • 이지용;김태호;정영덕;박정보;김순경;전언찬
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.1117-1122
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    • 2003
  • The paper on table deflection by stop state and move speed at loaded load, and the table deflection measured of static load. It is developed program for Date correction of LSM(Least Square Method). We experimented the method as following. The first a Laser setting and scan Experimental device measured curvature radius, The second A center of measurement object and curvature radius taking of LSC.

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양방향 층밀리기 간섭계를 이용한 긴 곡률반경 측정 (Measurement of Long Radius of Curvature by Using Bidirectional Shearing Interferometer)

  • 이윤우;조현무;이인원
    • 한국광학회지
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    • 제5권2호
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    • pp.198-203
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    • 1994
  • 구면의 긴 곡률반경을 측정하기 위하여 양방향 층밀리기 간섭계를 이용하는 새로운 방법을 제시하였다. 시준장치의 광원을 미세이동시켜 출사광선의 곡률중심과 시험구면의 초점을 일치시키는 비시준 조명방법을 사용하였으며 양방향 층밀리기 간섭계를 사용하여 시험구면에서 출사한 광선의 시준 여부를 정확히 확인하였다. 이 방법은 렌즈의 긴 초점길이도 측정할 수 있으며 여러가지 변수에 의한 측정정확도를 자세히 분석하였다.

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푸리에 변환을 이용한 파면위상의 복구 (Fourier transform method of surface topography and interferometry)

  • 남기봉
    • 한국광학회지
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    • 제3권1호
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    • pp.20-26
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    • 1992
  • Twyman-Green형 간섭계의 시험파면의 변형을 추출하기 위하여 fourier변환을 이용하는 방법을 모사실험과 실험을 통하여 검토하였다. 대상 방법중에서는 Takeda의 방법이 변형을 추출하는 용도로 적절함이 밝혀졌다. 이 방법을 평면경에 적용하여 얻은 표면의 구조에는 curvature가 존재하며, 그 크기는 $\lambda$/6정도였다. 이 축정의 정확도는 $\lambda$/40정도로 얻어져, 기 발표된 유사연구의 결과보다 그 정도가 높음을 확인하였다.

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경침 자가 운동 프로그램을 병행한 침 치료가 경추 만곡도와 심부 굴곡근 근력 변화에 미치는 영향 (Effect of Acupuncture Combined with Wooden Neck Pillow Self-exercise Program on Cervical Curvature Measurement Methods and Deep Flexor Muscle Strength)

  • 권정국;금동호
    • 한방재활의학과학회지
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    • 제27권1호
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    • pp.37-51
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    • 2017
  • Objectives This study was designed to identify the effect of acupuncture combined with wooden neck pillow self-exercise program (WSP). Methods 25 eligible subjects with chronic neck pain were recruited from September 2015 to August 2016. Subjects were treated by acupuncture twice a week for 4 weeks, also were educated WSP and exercised every day for 4 weeks. They were assessed using PI-NRS, NDI and the maximum muscle strength of deep cervical flexor muscles (DCF) before and after treatment. Also the Cobb's angle (C1-C7), Ishihara index, Park method were assessed for evaluating the radiographical changes. Variables were compared using paired t-test. And correlates analysis was used for analyzing relationship between differentials in the maximum muscle strength of DCF and differentials in cervical spine curvature measurement methods. Results Among the 25 subjects, 4 subjects were lost to follow-up or excluded in accordance with the criteria. Significant differences on NRS, NDI and the maximum muscle strength of DCF were seen after treatment (p<0.001). In radiological finding, cervical spine curvature measurement methods were significantly increased (p<0.001, p<0.05, p<0.05). Differentials in the maximum muscle strength of DCF significantly correlates to differentials in Ishihara index (R=0.479, p<0.05). Conclusions Acupuncture combined with WSP may decrease neck pain intensity and associated disability, and also increase the muscle strength of DCF and cervical lordosis, in patients with chronic neck pain. Especially, Improving the muscle strength of DCF has a relationship with improving Ishihara index. However, due to the design of this study, this treatment can not be compared with other treatments. Future randomized project should be needed.

Structural damage localization using spatial wavelet packet signature

  • Chang, C.C.;Sun, Z.
    • Smart Structures and Systems
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    • 제1권1호
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    • pp.29-46
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    • 2005
  • In this study, a wavelet packet based method is proposed for identifying damage occurrence and damage location for beam-like structures. This method assumes that the displacement or the acceleration response time histories at various locations along a beam-like structure both before and after damage are available for damage assessment. These responses are processed through a proper level of wavelet packet decomposition. The wavelet packet signature (WPS) that consists of wavelet packet component signal energies is calculated. The change of the WPS curvature between the baseline state and the current state is then used to identify the locations of possible damage in the structure. Two numerical studies, one on a 15-storey shear-beam building frame and another on a simply-supported steel beam, and an experimental study on a simply-supported reinforced concrete beam are performed to validate the proposed method. Results show the WPS curvature change can be used to locate both single and sparsely-distributed multiple damages that exist in the structure. Also the accuracy of assessment does not seem to be affected by the presence of 20-15dB measurement noise. One advantage of the proposed method is that it does not require any mathematical model for the structure being monitored and hence can potentially be used for practical application.

하악 제 2 유구치 근관 만곡의 방사선학적 계측 (THE RADIOGRAPHICAL MEASUREMENT OF ROOT CANAL CURVATURE OF MANDIBULAR PRIMARY 2ND MOLARS)

  • 김영종;정태성;김신
    • 대한소아치과학회지
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    • 제30권4호
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    • pp.637-642
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    • 2003
  • 유치근의 치근이개와 만곡에 관련된 형태학적 특성은 치열교환기의 치근 흡수 및 근단 병소의 양상을 결정지을 뿐 아니라, 성공적인 치수치료에 심대한 영향을 미친다. 본 연구는 하악 제 2유구치 근관 만곡의 각도, 반경 및 만곡 시작점을 측정해 봄으로써, 유치근과 근관의 해부학적 형태를 정밀 분석할 목적으로 시행되었다. 연구재료로는 $3{\sim}6$세의 어린이의 제 2 유구치 구내 치근단 방사선 사진 50매를 사용하였다. 근단공이 미완성이거나 흡수된 것을 제외하고, 방사선상의 왜곡이 적으며 근관 형태의 판독이 가능한 것을 선택하고, 자료를 digital image화하여 이미지 분석용 software Scion Image Beta 4.02 (Scion Co. USA)를 이용하여 만곡을 분석하였다. 그리고 Schneider법에 의해 만곡도를 측정하고, Schaefer 등의 방법에 의해 만곡반경을 측정하였으며, 아울러 만곡개시거리를 측정하고 근원심근 간의 비교를 통하여 다음과 같은 결과를 얻었다. 1. 제 2유구치의 만곡도는 근심근에서 $17.3^{\circ}{\pm}5.0$, 원심근에서 $27.9^{\circ}{\pm}6.0$로 원심근에서 크게 나타났다(p<0.05). 2. 만곡반경은 근심근에서 $8.7\;mm{\pm}2.5$, 원심근에서 $5.8\;mm{\pm}1.5$로 근심근에서 크게 나타났다(p<0.05). 3. 만곡개시거리는 근심근에서 $4.1\;mm{\pm}0.6$, 원심근에서 $4.2\;mm{\pm}0.6$로 양 근간에 차이가 없었다(p<0.05).

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광 간섭 현상을 이용한 나노 스케일의 유막두께 측정 (The measurement of Nano Scale film thickness using optical interferometry)

  • 윤영선;전필수;김현정;유재석
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.3178-3182
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    • 2007
  • The interferometer method with nano-scale spatial resolution has been developed in this study. To enhance the accuracy of the previous developed method, the 14 bit cooled CCD camera with 1280 by 980 spatial resolution was applied to the measurement. And optical alignment has been carried out on the highly accurate position sensors with 500nm resolution so as to be able to calibrate the detected interference image with the field of view. Also the measurements were applied to the ultra thin oil film between the Al coated cylinder mirror with 38.1mm radius and 0.5mm cover glass to verify the developed method. The measured result showed the good agreement with the used cylinder curvature with ${\pm}$5.18run uncertainty.

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수퍼 샘플링과 보간을 이용한 생물조직 영상의 면적 측정 (Area Measurement of Organism Image using Super Sampling and Interpolation)

  • 최선완;유숙현
    • 한국멀티미디어학회논문지
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    • 제17권10호
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    • pp.1150-1159
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    • 2014
  • This paper proposes a method for extracting tissue cells from an organism image by an electron microscope and getting the whole cell number and the area from the cell. In general, the difference between the cell color and the background is used to extract tissue cell. However, there may be a problem when overlapped cells are seen as a single cell. To solve the problem, we split them by using cell size and curvature. This method has a 99% accuracy rate. To measure the cell area, we compute two areas, the inside and boundary of the cell. The inside is simply calculated by the number of pixels. The cell boundary is obtained by applying super sampling, linear interpolation, and cubic spline interpolation. It improves the error rate, 18%, 19%, and 120% respectively, in comparison to the counting method that counts a pixel area as 1.