• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.29-38
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• 1992

무인화된 대량생산 체제에서는 transfer line을 이용하게되며, cycle time의 단축을 위하여 측정 및 검사기능이 별도의 station으로 있어 가공후에 부품의 불량여부를 감지한다. 그러나 다품종소량생산체제에서는 FMC 또는 FMS가 적합하며, 이 시스템에 바람직한 감시기능으로서는 기내측정(inter-process)방식을 많이 이용한다. 여기서는 CNC선반과 머시닝센터에 접촉식 센서인 터치프로브(touch probe)를 설치하여 개발한 무인 FMC용 인터프로세스 3차원 측정 및 검사시스템을 소개한다.

• Journal of the KSME
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• v.32 no.2
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• pp.175-183
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• 1992

모아레토포그라피를 이용한 금형제작을 위한 클레이모형(clay model)의 3차원 형상측정을 위한 방법이 제시되었다. 그리고 모아레무늬를 해석하는 방법이 제시되어 클레이모형의 형상을 측정 하였고 디지털영상처리기법을 사용하는 일련의 과정을 통해 3차원 형상을 재현하였다. IBM PC/386과 CCD 카메라를 사용하여 실험한 결과 0.005mm의 분해능을 가지며 측정속도가 5분 가량이 소요되었다. 따라서 광학적방법이 접촉식 디지타이징을 이용하였을 경우 발생하는 많은 문제점 등을 효율적으로 보완할 수 있다. 그리고 품질검사를 자동화할 수 있는 방법을 제시하 였고 기존의 모아레토포그라피가 가지는 어려움을 극복하기 위하여 새로운 방법인 주사식 모아 레토포그라피를 제시하였다.

• The Korean Journal of Applied Statistics
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• v.32 no.1
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• pp.15-27
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• 2019

The reliability of the data means the overall consistency of the measurement results. Methods for evaluating reliability have been continuously studied because it affects the results of the statistical analysis. Cronbach's ${\alpha}$ coefficient or intraclass correlation coefficient is used for reliability evaluation; however, these measures cannot be applied to data consisting of three-dimensional coordinates to represent an object. In this study, we propose a measure to evaluate the reliability of three dimensional shapes based on statistical shape analysis that is made possible by extracting the shape information from the measured three dimensional coordinates and decomposing the shape variation.

• 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.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.264-273
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• 2002

Purpose : Three-dimensional radiation dosimetry using magnetic resonance imaging of polymer gel was recently introduced. This dosimetry system is based on radiation induced chain polymerization of acrylic monomers in a muscle equivalent gel and provide accurate 3 dimensional dose distribution. We planned this study to evaluate the clinical value of this 3-dimensional dosimetry. Materials and Methods: The polymer gel poured into a cylindrical glass flask and a spherical glass flask. The cylindrical test tubes were for dose response evaluation and the spherical flasks, which is comparable to the human head, were for isodose curves. T2 maps from MR images were calculated using software, IDL. Dose distributions have been displayed for dosimetry. The same spherical flask of gel and the same irradiation technique was used for film and TLD dosimetry and compared with each other. Results : The R2 of the gel respond linearly with radiation doses in the range of 2 to 15 Gy. The repeated dosimetry of spherical gel showed the same isodose curves. These isodose curves were identical to dose distributions from treatment planning system especially high dose range. In addition, the gel dosimetry system showed comparable or superior results with the film and TLD dosimetry. Conclusion : The 3-dimensional dosimetry for conformal radiation therapy using MRI of polymer gal showed stable and accurate results. Although more studies are needed for convenient clinical application, it appears to be a useful tool for conformal radiation therapy.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.12 s.148
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• pp.1595-1607
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• 2005

Three-dimensional(3-D) body scanners used to capture anthropometric measurements are now becoming a common research tool far apparel. This study had two goals, to test the accuracy and reliability of 3-D measurements of dynamic postures, and !o analyze the change in upper body surface measurements between the standard anthropometric position and various dynamic positions. A comparison of body surface measurements using two different measuring methods, 3-D scan measurements using virtual tools on the computer screen and traditional manual measurements for a standard anthropometric posture and for a posture with shoulder flexion were $-2\~20mm$. Girth items showed some disagreement of values between the two methods. None of the measurements were significantly different except f3r the neckbase girth for any of the measuring methods or postures. Scan measurements of the upper body items showed significant linear surface change in the dynamic postures. Shoulder length, interscye front and back, and biacromion length were the items most affected in the dynamic postures. Changes of linear body surface were very similar for the two measuring methods within the same posture. The repeatability of data taken from the 3-D scans using virtual tools showed satisfactory results. Three times repeated scan measurements f3r the scapula protraction and scapula elevation posture were proven to be statistically the same for all measurement items. Measurements from automatic measuring software that measured the 3-D scan with no manual intervention were compared with the measurements using virtual tools. Many measurements from the automatic program were larger and showed quite different values.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.10
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• pp.593-602
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• 2004

A new surface reconstruction scheme for approximating the surface from a set of unorganized 3D points is proposed. Our method, called shrink-wrapped boundary face (SWBF) algorithm, produces the final surface by iteratively shrinking the initial mesh generated from the definition of the boundary faces. Proposed method surmounts the genus-0 spherical topology restriction of previous shrink-wrapping based mesh generation technique, and can be applicable to any kind of surface topology. Furthermore, SWBF is much faster than the previous one since it requires only local nearest-point-search in the shrinking process. According to experiments, it is proved to be very robust and efficient for mesh generation from unorganized points cloud.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.227-232
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• 2016

3D body scan data are used widely in various fields to make products and living spaces for superior human body fitness. Based on the 3D measurements of human bodies for teens in Size Korea 2013, this research provides a way of finding the representative body sizes and 3D body scan data. First, a multi-dimensional vector space consisting of many measurement items was projected onto a 2D vector space with circumference and length components via factor analysis. The representative body sizes and 3D scan data close to these values were obtained via the Mahalanobis distance in 2D space. Considering the adolescent growth pattern shown on this 2D space, males were divided into 4 age groups and females were divided into 3 age groups. Using the eigenbodies corresponding to the column vectors of the component score coefficient matrix, the representative body sizes of 13 measurement items (male) and 14 measurement items (female) for each age group were calculated. The representative body sizes and 3D scan data are very useful for modeling representative 3D human figures.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2009.04a
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• pp.246-248
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• 2009

기존의 항공사진 및 위성사진을 활용한 원격탐사방법은 기상조건에 따른 제약과 3차원적 수직구조 관한 정보 수집에 한계가 있다. 따라서 보다 정확하고 신속한 산림자원 정보를 획득하기 위해서는 새로운 기술적 접근이 필요하다. 3차원 측정이 가능한 LiDAR의 특성을 이용하면 기존 방법의 부정확성과 비효율성을 상당부분 극복 할 수 있다. 본 연구에서는 지상 Laser Scanner 와 항공 LiDAR를 이용하여 개체목의 3차원 구조를 예측하여 수고, 지하고, 수관면적, 수관체적을 추정하고 결과를 비교하였다. 지상 Laser Scanner에 의한 측정치를 참조자료로 하여 항공 LiDAR의 개체목 측정 정확성을 향상 시킬 수 있는 보정식을 최종적으로 개발하였다.

• Korean Journal of Optics and Photonics
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• v.26 no.3
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• pp.147-154
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• 2015

We propose a method for simultaneously measuring the front and back surface profiles of transparent optical components. The proposed method combines dual-wavelength transmission deflectometry with liquids to record distorted phases at different wavelengths, and then numerically reconstructs the three-dimensional phase information to image the front and back surfaces of the lens. We propose a theoretical model to determine the surface information, and a bifocal lens is experimentally investigated. Unlike conventional transmission deflectometry, our proposed method supports direct observation of the front and back surface profiles of the optical elements.