• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.187-192
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• 1999

Noncontact measuring methodology of 3-dimensional profile using CCD camera are very attractive because of it's high measuring speed and its's high sensitivity. Especially when projecting a grid pattern over the object, the captured image have 3 dimensional information of the object. Projection moire extract 3-D information with another grid pattern in front of CCD camera. However phase measuring profilometry(PMP) obtain similar results without additional grid pattern. In this paper, the projection moire are compared with the PMP mathematically, and it is shown that PMP can generate moire image with simple mathematical computations. Experimental works are also carried out showing the same results. It is shown that using a single gird pattern, moire image can be obtained directly without any mathematical operation when some conditions are satisfied.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.3 no.2
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• pp.1-10
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• 1985

Moire technique is generally divided into shadow Moire Technique and Projection Moire Technique. In this paper, determinating the direction of reference planes for this system, by comparing the results of this system with those of general terrestrial photogrammetry, is an objective of this paper. For the objective, control surveying is done and the results of control surveying are compared with those of moire photograph. In this technique, it is found that though the positions of a projector and a reference grid are not moved, a desired moire contour whose the reference plane is different respectively is easily obtained by changing the pitches of a master grid and a reference grid on an object. Also it is found that when the pitches of the two grids on an object are equal, a moire contour which has the reference plane parallel to the object can be obtained.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.6
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• pp.25-31
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• 2000

"모아레(MOIRE)"란 말은 처음으로 프랑스인들에 의해 불려진 단어로써 고대 중국에서 수입된 비단 위에 새겨진 물결무늬(wave pattern)를 일컫는 말이다. 이렇게 불리어지던 모아레는 요즈음에 들어서서 두 개 이상의 주기적인 패턴(periodic pattern)이 겹쳐질 때 만들어지는 간섭무늬 (interference fringe)를 지칭하는 말로써 다양한 분야에서 매우 광범위하게 사용되어 지고 있다.(중략)

• The Journal of Korean Medicine
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• v.21 no.4
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• pp.148-158
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• 2000

Objective : The purpose of this study was to investigate the back shape of school children using the phase-shifting scanning grating projection moire interferometer, which was developed by the Korea Advanced Institute of Science and Technology and is useful in evaluating three dimensional back shape. Methods : In this study the subjects consisted of 1,358 pupils [711 boys(52.36%), 647 girls(47.64%)] attending elementary and middle schools in Seoul. Their ages ranged from nine to fifteen and the average age was 12.2. With the phase-shifting scanning grating projection moire interferometer, the posterior view of the body were taken to see if there are correlations of moire fringe number, width difference between left and right, and correlation between differences in moire fringe number and width on both sides in the scapular, lumbar and gluteal regions. Results : The results were as follows : I. More frequent findings of fringe were observed on the right in all regions : in the scapular region, 309 boys(43.4%) and 156 girls(24.2%) had more fringe numbers on the right side; in the lumbar region, 68 boys(9.5%) and 11 girls(1.7%); and in the gluteal region, 160 boys(22.4%) and 63 girls(9.8%). Such tendency was striking especially in the scapular and lumbar regions, and in boys rather than in girls. In the scapula, 661 subjects(48.7%) with one moire fringe on either side need further attention and 110 subjects(8.I %) with two or more are required to do follow-up radiography for scoliosis. 2. In an analysis of width difference in the trunk, the left side is wider in all regions except for the gluteal region in boys : in the scapular region 21 boys(3.0%) and 103 girls(15.9%); in the lumbar region, 87 boys(12.2%) and 250 girls(38.6%); and in the gluteal region 197 girls(30.4%) had a wider left side and 45 boys(6.3%) showed a wider right side. 3. In correlation analysis of the number of moire fringe and width difference in each region, the side where more moire fringes were observed was significantly wider in the lumbar and gluteal regions, but not in the scapular region.(p<0.01) Conclusions : From these results, it is concluded that the back shape of elementary and middle school students in Seoul shows that the right side had more moire fringes; the left side was wider; and especially in the lumbar and gluteal regions the side where more moire fringes were observed was wider.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.170-175
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• 1999

Noncontact measuring methodology of 3-dimensional profile using CCD camera are very attractive because of it's high measuring speed and its's high sensitivity. Especially, when projecting a grid pattern over the object the captured image have 3 dimensional information of the object. Projection moire extract 3-D information with another grid pattern in front of CCD camera. However phase measuring profilometry(PMP) obtain similar results without additional grid pattern. In this paper, new method for grid pattern generation system by polygonal mirror and Laser Diode. This system is applied the projection moire and the PMP.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.188-190
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• 1987

In this paper the real-time analysis of vibration objects using projection moir\ulcorner method is realized. By measuring the vibration of two different speakers using three grationgs with different pitch. it is possible to analyze the vibrating speakers, so the fundamental frequency mode of speakers is obserbed at 550Hz and 105Hz respectively and phase lag is shown nonlinear characteristics. Also it is possible to measure the vibration as to nonperiodic signals as well as peoriodic signals.

• Proceedings of the Optical Society of Korea Conference
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• 2007.07a
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• pp.63-64
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• 2007

• Journal of the Korean Society for Precision Engineering
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• v.22 no.4
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• pp.7-12
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• 2005

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.268-269
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• 2005

• Journal of the Korean Society for Precision Engineering
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• v.18 no.6
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• pp.159-165
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• 2001

Recently Moire and PMP(Phase Measuring Profilometry) are adopted as a practical methodology for non-contact 3-D measurement of free surface. These methods extract the 3-D informations from the images of the object projected with stripe-pattern light. This paper presents a simple projector generating stripe-pattern light using expensive polygon mirror. In this projector, slit-beam is generated with a Laser diode and a rod lens and the laser diode is switched on/off synchronizing with the rotation of the polygon mirror. So its structure is very simple and light-weighted compared to the existent projection methods using several lenses and it is also easy to change the pitch and the phase of the stripe pattern. Experimental results show that the intensity profile of the stripe pattern can be approximated with sinusoidal curve by reducing the pitch of the stripe pattern.