• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.9
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• pp.1276-1283
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• 2004

This study is an inspection of press forming product and mould using reverse engineering system. The inspection process on production field involves a lot of errors because of the hand-work so we focussed on improving the measured precision through performing the effective inspection using 3D non-contact scanner. By so doing that, we improved the precision of press forming product by analyzing the cause following the inspection result. Through the inspection, we applied it to the reverse engineering and we could improve the inspection process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.10
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• pp.1702-1711
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• 1997

A numerical study for the number of terms of a power series stress function and the effect of hybrid element size on stress analysis around a hole in loaded orthotropic composites is presented. The hybrid method coupling experimental and/or theoretical inputs and complex variable formulations involving conformal mappings and analytical continuity is used to calculate tangential stress on the boundary of the hole in uniaxially loaded, finite width glass epoxy tensile plate. The tests are done by rarying the number of terms, element size and nodal locations on the external boundary of the hybrid region. The numerical results indicate that the hybrid method is accurate and powerful in both experimental and numerical stress analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.220-223
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• 1997

Moire topography method is a well-known non-contacting 3-D measuement 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 projection moire topography is very attractive because of it's high measuring speed and high sensitivity. In this paper, using two-wavelength method of projection moire topography tested to measuring object with the 2x-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding absolute fringe orders, so that the 2x-ambiguity problem can be effectively overcome so as to treat large step discontinuities in measured objects.

• Information and Communications Magazine
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• v.31 no.3
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• pp.62-68
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• 2014

1938년 찰스 휘트스톤이 영국 런던 왕립협회지에 양안시 현상에 대한 연구를 발표한 이후 3차원 디스플레이 기술은 진보를 거듭하고 있다. 최근에는 넓은 시역에서 다수의 사용자가 시청할 수 있는 초다시점 디스플레이 개발이 진행 중이다. 그러나 현재 초다시점 방식의 낮은 해상도, 무아레, 크로스톡 등은 여전히 해결해야 할 과제로 여겨지고 있다. 따라서 본고에서는 현재 각광받고 있는 초다시점 디스플레이 관련 휴먼팩터 요인을 조명하고 가능한 평가 방법들에 대하여 기술한다. 통합적 휴먼팩터 평가 방법의 개발을 통해 초다시점의 시스템 요인과 매핑할 수 있는 모델링 연구가 선행된다면, 인간 친화적 초다시점 디스플레이 개발에 많은 기여를 할 것으로 예상된다.

• Korean Journal of Optics and Photonics
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• v.3 no.3
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• pp.172-177
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• 1992

Improved technique for collimation testing based on bidirectional shearing interferometry is presented. It consists of a wedgc. plate and two plane mirrors. The proposed technique has its own reference mark to indicate collimation of the light beam and provides a two fold increase in sensitivity. Detailed analyses for various configurat~ons are presented, and the usef~llness for practical applications is demonstrated.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.144-145
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• 2021

Variable range of focal length of Moiré lens is designed to change the phase pattern, which is varifocal lens system using two thin layers with Moiré pattern and suitable to applied to AR/VR system because of the relatively simple structure, large aperture size, and wide variable range. We analyze the change of focal length region according to the phase pattern and verify the design to make the prototype patterns using DOE.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.3
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• pp.37-44
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• 2013

It is well known that thermal deformation of electronic packages with Pb-Sn solder and with lead-free solder is significantly affected by material properties consisting the package, as well as those of the solder itself. In this paper, the method for determining coefficient of thermal expansion(CTE) of new material is established by using temperature characteristic of strain gages, and the CTE of molding compound are obtained experimentally. The temperature-dependent CTE of molding compound for Pb-Sn solder and that for lead-free solder are obtained by using strain measurements with well known steel specimen and aluminium specimen as reference specimens, and the CTE's are also measured non-contactly by using moire interferometry. Those results are compared, and the agreement between the two types of strain gage experiment and the moire experiment show the strain gage method used in this paper to be reliable. In the case of the molding compound for Pb-Sn solder, the CTE is measured as approximately $15.8ppm/^{\circ}C$ regardless of the temperature. In the case for the lead-free solder, the CTE is measured as of approximately $9.9ppm/^{\circ}C$ below the temperature of $100^{\circ}C$, and then the CTE is increased sharply depending on the temperature, and reaches to $15.0ppm/^{\circ}C$ at $130^{\circ}C$.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.8
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• pp.1125-1136
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• 2000

Fitness of clothes becomes a major concern in apparel industry. Development of basic patterns will enhance the fitness of clothes. But there are few slacks patterns for the middle-high school girls. So girls had difficulties to buy ready-made clothes of good fit. To solve this problem, it is necessary to develop basic slacks patterns. The purposes of this study was to develop basic slacks patterns based on the analysis of lower body types. 4 girls were selected among 402 anthropometric measurement subjects who are 13 to 15 year-old for the wearing tests. The result of this study can be summarized as follows; 1. Analysing the replicas of lower body surface by using gypsum method, slack patterns were developed. 2. Wearing test by the sensory evaluation showed that the developed slacks pattern was estimated more highly than existing patterns in the items of the comfort of front crotch and back crotch. 3. Wearing test by moire topography method represented that garment silhouette of developed slacks pattern was estimated more highly and garment space of waist, hip were significantly different among patterns.

• Journal of the Korean Home Economics Association
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• v.40 no.6
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• pp.185-195
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• 2002

This study was carried out to investigate the wearing silhouette of jackets according to the mechanical properties, primary hand value and total hand value of the 3 types of wool fabrics. Wool/PET(50/50), wool/PET(80/50) and wool(100%) fabrics were used as test specimens. Mechanical properties of specimens were measured by KES-FB system and primary hand value and total hand value were calculated by equation KN-203-LDY. We made three experimental jackets based on the precious jacket pattern and used Moir Photography to measure the amounts of space between the jacket clothes and body surface from the overlap cross section map. The results were as follows: 1) In mechanical properties, woo/PET(80/20) fabric showed higher bending and shear rigidity. 2) In evaluation of primary hand and total hand, wool 100% fabric showed higher NUMERI and FUKURAMI hand and total hand value. 3) From the reset of Moir Photography, the wearing shapes of the experimental jackets were influenced by the characteristics of fabrics. Except for the hip part, the garment ease of wool/PET(80/20) fabric was estimated more highly.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.292-295
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• 2003

Moire topography method is a well-known non-contacting 3-D measurement method. 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 study, digital two-wavelength phase shilling moire is applied to the entertainment fields. recently. as promoting the growth of the VR-Game, display devices which attract public attention such as HMD or Projector are being appeared in order to deliver effectively the absorption sense. this study realized the Auto-calibrating system for arbitrary display surface using digital moire method which satisfied the shape measurement of display surface and the request of FOV(Field of View) output. also when large screen wasn't prepared, this auto-calibrating system was applied to enjoy games or movies at home with a projector and walls