• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.11a
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• pp.111-115
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• 1998

A phase-shifting projection moire method particularly intended for high-speed three-dimensional shape reconstruction of diffuse objects is presented. Emphasis is on realization of phase-shifting fringe analysis in projection moire topography using a set of line grating pairs designed to provide different phase shifts in sequence. Further a time-integral fringe capturing scheme is devised to remove undesirable high frequency original grating patterns in real-time without time-consuming software image processing. Finally the performances of the proposed method are discussed with measurement results.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.6
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• pp.210-217
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• 2000

Noncontact measuring methodology of 3-dimensional profile using CCD camera are very attractive because of it's high measuring speed and it'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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.199-202
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• 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.

• 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.

• 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.

• 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)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2457-2462
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• 2011

The need for rapid and accurate measurement of 3-dimensional objects is increasing due to the paradigmatic shift in manufacturing from mass production to small batch production. A three dimensional measurement technique which can provide the dimensional information of the object manufactured or to be manufactured has been developed. This method is based on phase shifting moire topology. Digital-Micromirror-Device (DMD) has been used in generating phase shifting moire fringes. And the mechanically moving optical components used for phase shifting, which might result in measurement errors, have been replaced by the DMD. Inherent $2\pi$-ambiguity problem, occurring in the calculation of phase from the light intensity distribution due to the nature of arctangent function, has been overcome by adapting the phase unwrapping method. The advantage of this technique is the easy change of the range and the resolution of the measurement by simply changing the computer generated grid pattern with the appropriate combination of projection lens of various focal length.

• 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

• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.12-21
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• 2003

• The Journal of Pediatrics of Korean Medicine
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• v.17 no.2
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• pp.55-74
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• 2003

Objective : The purpose of this study was to investigate the back shape and self-conscious symptoms of the students in S High school using the phase-shifting scanning grating projection Moire interferometer and Questionnaire investigations. Methods : In this study the subjects consisted of 317 pupils[168 boys(53%), 149girls(47%)] attending S high school in Sungnamsi, Kyoungkido in 2002. Their ages ranged from sixteen to eighteen. With the phase-shifting scanning grating projection moire interferometer, the posterior views of the body were taken to see if there are correlation of remainder value of the height spot of left & right shoulder blade and gluteal region in Moire topography. And using questionnaire investigation, we investigated the self-conscious symptoms. Results : 1. In questionnaire investigation, we observed that the ratios of self-conscious symptoms of girls are more than that of boys. The ratios of headache, neck pain, lower back pain, digestive symptom were more than 70% in boys and girls. 2. In Moire topography, more frequent findings of scapular region were observed that left scapular area were higher than right(in boys 69.3%, 60%, 100%, aged 16,17,18, in girls 66.8%, 40.5%, 58.8% aged 16,17,18). 3. More frequent findings of gluteal region were observed that left scapular area were higher than right(in boys 75.2%, 60%, 36.4% aged 16,17,18, in girls 61.1%, 46.8%, 64.7% aged 16,17,18) 4. More frequent findings of reminder value of the vertical lines of cervical and buttock region in Moire topography were observed that the vertical lines of cervical region were inclined to left than the vertical lines of buttock(in boys 73.3%, 92.2%, 100% aged 16,17,18, in girls 72.2%, 77.2%, 73.5% aged 16,17,18) Conclusion : From these results, we found that the self-conscious symptoms were more than in girls than boys; the ratio of headache, neck pain, Lower back pain, digestive symptom was more than the others; the back shape of high school students were not balanced in scapular and buttock region; necks were inclined to left than buttock.