• Title/Summary/Keyword: Moire Method

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Studies on the theory of Oriental Medicine Diagnosis and applicatin of Moire topography (한의학적(韓醫學的) 진단원리(診斷原理)와 모아레 토포그래피의 응용(應用))

  • Lee, Jae-Won
    • Korean Journal of Oriental Medicine
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    • v.1 no.1
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    • pp.273-287
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    • 1995
  • Moire topography, a simple technique for three-dimensional quantitation, was used to provide interference fringe photographs of the human back with sufficient accuracy to be used for detecting patient with asymmetry due to scoliosis, the disease of cervix and lumbar, muscle dysfunction. Contour lines are a suitable and widely accepted method of describing a three-dimensional surface. In the moire technique, contour lines of an object are produced as interference fringes while the object is illuminated by a spotlight through a special grating. The fringe pattern is produced by the interference of the grating and its shadow on the object. A photograph of a moire pattern on the human back will permit an assessment of the overall body shape and the symmetry of the back. This study uses shadow moire topography. Moire topography provides a non-invasive technique for quantifying the shape of the human body. In the use of moire topography for the Oriental Medicine Diagnosis, the strength of moire lies in the ablility to detect change due to deformity of human body.

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The Creep Behavior of Austentic SUS 27 by Moire Method (모아레法 을 活용 比較한 오우스테나이트系 SUS 27 의 크리이프擧動)

  • 옹장우;이훈주
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.7 no.1
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    • pp.46-51
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    • 1983
  • This study practiced to observe the creep behavior at specific temperature on Austentic SUB 27 stainless steel by Moire method. The results obtained from this study are summarized as follows; In tensile experiment, tensile strength and yielding strength decrease as the temperature increases. Yielding strength is equivalent to 60-70% of tensile strength. Reduction of Area and Elongation show minimum values at 300.deg. C. The results of Moire method using Moire heating resisting grid coincide with LVDT result. Therefor, It is proved that the Moire method has great merit in strain measurement of a creep behavior. In homologous at temp. 0.2 or less, creep behavior is very small amount. But, in more than 0.3, creep behavior is very active. Creep rate increase as temperature increase and creep rate is proportional to .alpha. values of experimental equation.

Improvement of accuracy of surface measurement in the phase-shifting shadow moire method (위상이동 그림자 무아레방법에서 형상측정 정확도의 개선)

  • 유원재;강영준;권기용
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.402-406
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    • 1995
  • The shadow moire is one the optical techniques which able to give contour lines of an object with respect to a master grating plane. The moire patterns are issued from the superposition of a grating and its shadow projected on the surface of an object. But in the conventional shadow moire method the reference grating and deformed grating are mutually dependent, it is impossible to obtain uniform phase shifts on the whole field by moving the reference grating. Here we propose ane trial to apply phase shifting to conventional shadow moire. When, in the conventional arrangement, Phase-shifting that is sctually constant regardless of fringe orders is achieved by moving the grating and the light source. Finally we obtained a better result by using this procedure and applied the phase shifting shadow moire to three dimensional measurement.

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Clinical Study on the Correlation between 3-Dimensional MOIRE Topography and Questionnaire for School Screening in Scoliosis (척추측만증 검진을 위한 모아레 체형측정법과 설문조사의 상관성 연구)

  • Yoo, Han-Keel;Kim, Hae-Jung;Shin, Byung-Cheul
    • The Journal of Korea CHUNA Manual Medicine
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    • v.4 no.1
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    • pp.141-153
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    • 2003
  • Objectives : The purpose of this study is researching for correlation between Moire topography results and questionnaire which include obesity rate, height, weight, posture, pain aspect (low back pain, headache, fatigue, neck pain etc), studying posture, school attendance method, menarche. Methods : The authors practiced Moire topography and questionnaire for primary & middle school 24,419 students [male 12,843, female 11,576] in Jeonbuk, korea in 2002. After we distinguished students who had abnormal finding in Moire topography and statistically analysed the data. Results : According to this research, the abnormal finding in Moire topography results was 37.3% (9,105 students), and students needed X-ray re-examination were 3.9% (953 students). According to statistical analysis, male/female and primary/middle school students have no difference in deformity degree of the body surface examined by Moire. Height and weight have low correlation with deformity degree of the body surface examined by Moire and menarche, pain aspect have no correlation. But, school attendance method by bicycle and $90^{\circ}$upright sitting in study posture is the best way to decrease the deformity degree of the body surface examined by Moire. Conclusions : Following this research, throughout Moire topography could detect trunk asymmetry that couldn't be found existing X-ray examination, and school attendance by bicycle and $90^{\circ}$upright sitting in study posture is good for school students to prevent back deformity.

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Normalization of the Misaligned Moire Pattern Using Fourier Transform (푸리에 변환을 이용한 미스얼라인된 Moire 무늬의 표준화)

  • Park, T.W.;Morimoto, Y.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.15 no.2
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    • pp.386-394
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    • 1995
  • The fringes developed by misalignment, an application of Moire method measuring small deformation of specimen, was transformed to frequency function. After that, theory of normalization was applied to derive the equations explaining the relation of the deformation and Moire fringes. Above all, the equations were produced to explain the rotation and increasing of fringes. In addition to that, the relation of fringe number and strain was illustated with the equations deduced from frequency function and geometrical method respectively. These two expressions were more effective than the used ones owing to the one can accommodate the other.

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A Study on the Improvement of Accuracy of Surface Measurement in the Phase-Shifting Shadow Moir$\'{e}$ Method (위상이동 그림자 무아레방법을 이용한 형상측정법의 정확도 개선에 관한 연구)

  • 강영준;유원재;권용기
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.10
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    • pp.96-102
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    • 1998
  • In this study, the theory and application of phase-shifting shadow moire topography is focused on the non-contact measurement of object surfaces for practical use in the field of production engineering. Shadow moire topography has been studied during last few decades in the area of the optical physics, and now its mathmatical theory has been established. Generally, in case of the classical shadow moire topography, the sensitivity is a few tenths of millimeter in best cases. Here we tried the application of phase-shifting method to the conventional shadow moire topography. But the reference grating and the deformed grating are mutually dependent because it is impossible to obtain uniform phase shifts on the whole Held. Therefore it is difficult to use a phase-shifting method in shadow moire topography. However, it was shown that constant phase-shifting was able to be measured by moving both the grating and light source. Finally we obtained a better result by using this procedure and applied the phase-shifting shadow moire to three dimensional object measurement.

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A New Error Compensation Method in Linear Encoder Using a Phase-Modulated Grating (위상 변환 격자를 이용한 선형 엔코더의 오차 보상법)

  • Song, Ju-Ho;Kim, Gyeong-Chan;Kim, Su-Hyeon;Gwak, Yun-Geun
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.10
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    • pp.147-154
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    • 2000
  • A new hardware compensation method reducing displacement measurement errors, caused by tilt of index scale in moire linear encoders, has been developed. In conventional moire linear encoders, the detectors are aligned perpendicular to the line of moire fringes this structure is very sensitive to an unwanted tilt of the gratings. In this paper, a newly designed grating, called a phase-modulated grating, is developed to compensate for non-orthogonal errors. By using the phase-modulated grating instead of a conventional index, it is possible to reduce non-orthogonal errors of moire linear encoders.

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Study on Bulge Test by Moire Method (모아레法 에 의한 벌지試驗 에 관한 硏究)

  • 백남주;지용주;강대민
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.7 no.3
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    • pp.286-293
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    • 1983
  • This study measures polar compressive thickness strain and radius of curvature of the bulge through Moire' method in bulge test. Hill's and Alexander's bulge theories, instability conditions derived by Swift's, Hill's, Alexander's and wang's theories, are also investigated, compared with Moire' experimental results. In order to review and compare with Hill's and Alexander's bulge theories, the relationships between radius of curvature of the bulge and polar height, between polar compressive thickness strain and polar height, are used. Mild steel, soft copper and commercial pure aluminum are used in Moire' experiment. According to this study, Hill's and Alexander's bulge theories, instability conditions derived by Swift's, Hill's, Alexander's and Wang's theories are agreement to Moire' experiment results.