• Title/Summary/Keyword: 모아레 법

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A Study on the Grating Projection Method using Polygon Mirror (회전다면경을 이용한 줄무늬 격자 영사방법에 관한 연구)

  • Park, Yoon-Chang;Jeong, Kyung-Min;Jang, Seok-Jun;Park, Kyung-Keun
    • 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.

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A Robust Method for Automatic Generation of Moire Reference Phase from Noisy Image (노이즈 영상으로부터 모아레 기준 위상의 강인 자동 생성 방법)

  • Kim, Kuk-Won;Kim, Min-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.5
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    • pp.909-916
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    • 2009
  • This paper presents the automatic vision algorithm to generate and calibrate reference phase plane to improve the accuracy of 3D measuring machine of using phase shifting projection moire method, which is not traditional N-bucket method, but is based on direct image processing method to the pattern projection image. Generally, to acquire accurate reference phase plane, the calibration specimen with well treated surface is needed, and detailed calibration method should be performed. For the cost reduction of specimen manufacturing and the calibration time reduction, on the specimen, not specially designed, with general accuracy level, an efficient calibration procedure for the reference phase generation is proposed. The proposed vision algorithm is developed to extract the line center points of the projected line pattern from acquired images, derive the line feature information consisting of its slope and intercept by using sampled feature points, and finally generate the related reference phase between line pairs. Experimental results show that the proposed method make reference phase plane with a good accuracy under noisy environment and the proposed algorithm can reduce the total cost to make high accurate calibration specimen, also increase the accuracy of reference phase plane, and reduce the complex calibration procedure to move grid via N-bucket algorithm precisely.

Research for Bit-depth Conversion Development by Detection Lost Information to Resizing Process for Digital Photography (디지털 사진영상의 크기조절과정에서 유실되는 정보를 이용한 비트심도의 확장)

  • Cho, Do-Hee;Maik, Vivek;Paik, Joon-Ki;Har, Dong-Hwan
    • The Journal of the Korea Contents Association
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    • v.9 no.4
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    • pp.189-197
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    • 2009
  • A digital image usually has 8 bits of depth basically representing pixel intensity ranging for [0 255]. These pixel range allow 256 step levels of pixel values in the image. Thus the greyscale value for a given image is an integer. When we carry out interpolation of a given image for resizing we have to round the interpolated value to integer which can result in loss of quality on perceived color values. This paper proposes a new method for recovering this loss of information during interpolation process. By using the proposed method the pixels tend to regain more original values which yields better looking images on resizing.

A Comparative Study on the Balance of Musculoskelectal System between Long-Term Employed Male Taxi Drivers and General People - through Moire Topography (장기근속 남성 택시기사와 일반인의 근골격계 균형에 관한 비교 연구 - 모아레 체형측정법을 통해)

  • Lim, Sang-Hoon;Park, Dong-Su;Lee, Kyung-Moo;Jeong, Su-Hyeon;Kim, Soon-Joong
    • Journal of Korean Medicine Rehabilitation
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    • v.18 no.1
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    • pp.141-151
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    • 2008
  • Objectives : The purpose of this study was to investigate effects of long-term taxi driving posture on the balance of musculoskelectal system. Methods : The author practiced Moire topography by using IBS-2000 for 30 male taxi drivers and general people. Then we measured difference of contour lines, difference of shoulder joint height, interval between vertical baseline of pelvis and vertical baseline of neck, ratio of thoracic curve and lumbar curve, difference of width between right and left through Moire topography. After we statistically analyzed difference of Moire topography's data between long-term employed male taxi drivers and general people. Results : 1. Taxi drivers, difference of contour lines in scapular, lumbar, gluteal region was bigger than general people and significant difference(p<0.05) was observed between subject group. 2. Taxi drivers, diference of shoulder joint height was more large than general people and significant difference(p<0.01) was observed between subject group. 3. Taxi drivers, diference of interval between vertical baseline of pelvis and vertical baseline of neck was more large than general people and significant difference((p<0.05) was observed between subject group. 4. Taxi drivers, ratio of thoracic curve was more large than general people and ratio of lumbar curve was more less than general people and significant difference(p<0.05) was observed between subject group. Conclusions : According to above results long-term taxi driving posture might cause musculoskelectal system unbalance.

A Study of the Relationship between Spine Distortion and Pain of Elementary and Middle School Students - through moire measurement and questionnaire investigation - (초.중학생의 척추비틀림과 통증과의 관계고찰 - 경근무늬(모아레) 측정법과 설문지 조사를 통해 -)

  • Yoo, Han-Keel;Shin, Byung-Cheul;Min, Byung-Il
    • The Journal of Korea CHUNA Manual Medicine
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    • v.2 no.1
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    • pp.133-142
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    • 2001
  • Objectives : The aim of this study is to investigate the relationship between spinal distortion and pain in elementary and middle school students. Methods : Using the phase-shifting moire developed by KAIST(Korea Advanced Institute of Science and Technology) we measured the back surface distortion, and using questionnaire investigation, we investigated the partial pain in 1008 elementary and middle school students(532 boy students(52.8%), 476 girl students(47.2%)) in Seoul in 1999. And, we statistically analyzed the relationship between spinal distortion and partial body pain Results : This study show that the more age increase, the more the pain in head, neck, shoulder, back and low back Increase considerably among the students aged 9 to 15. The ratio of each partial body pain was 28.4%, 19.7%, 18.2%, 18.7%. 16.0% at the age of 9 and 59.7%, 67.4%, 51.8%, 51.8%, 64.4% at the age of 15 respectively. And, it was shown there was a significant correlation between spine distortion and partial body pain area. When the spinal distortion was found at the upper thoracic and cervical area, the students complained the more pain on head, neck and shoulder(p<0.05) and when the spinal distortion was found at the sacral base, the more headache(p<0.05) Conclusions : It is suggested that the significant correlation exist between the spinal distortion and pain and the pain related to spine disorder get more increase as students grow. We have to study further more about Juvenile postural distortion and it's prevention.

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A Study on the Back shape and self-conscious symptoms of the students in S High school Using the Moire measurement and Questionnaire investigation (모아레 측정법과 설문지 조사를 통한 경기도 S고등학교 재학생의 신체자각증상과 배부체형에 대한 실태조사)

  • Chang, Gyu-Tae;Kim, Jang-Hyun;Baek, Hyun
    • 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.

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