• Title/Summary/Keyword: 영사식 무아레 방법

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2중파장 영사식 무아레의 N-Buckets 알고리즘 오차비교에 관한 실험적 연구

  • 유원재;박낙규;강영준
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.05a
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    • pp.181-181
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    • 2004
  • 3 차원 형상측정기술(3-D Profile Measurement Method)은 가공품의 치수검사 및 형상측정 등의 공학분야뿐만 아니라 최근에는 의류산업 및 의학산업은 물론 오락산업의 가상현실 구현 등 여러 분야로 점차 사용이 확대되고 있다. 이러한 요구를 만족시킬 수 있는 광학을 바탕으로 한 비접촉 3 차원 형상측정방법(Non-contacting 3-D Profile Measuring Method)은 고속, 고정밀도 측정이 가능하기 때문에 활발히 연구되고 있다. 광학을 이용한 대표적인 3 차원 비접촉 측정방법의 하나인 영사식 무아레는 그림자식 무아레의 단점인 격자의 크기가 측정물체보다 커야 한다는 점과 측정물체와 격자사이의 거리 제한 문제를 해결하였으며, 위상이동법을 사용함으로서, 무아레 무늬 형태의 영향을 받지 않고 측정이 가능해졌다.(중략)

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Moire fringe contrast due to surface slope of an object in additive type moire topography (덧셈 방식 무아레 토포그래피에서 물체의 경사각에 따른 무아레 무늬의 가시도)

  • 류재명;조재흥;임천석;강호동;김태현
    • Proceedings of the Optical Society of Korea Conference
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    • 2002.07a
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    • pp.202-203
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    • 2002
  • 무아레 무늬는 주기적인 두 격자에 비간섭성 광원을 사용하여 얻을 수 있으며, 격자의 모양에 따라 측정 물체의 병진 운동 및 회전 운동 측정이 가능하다. 무아레 기술은 비접촉식 측정 방법으로 실험 장치가 단순하여 물체의 3차원 형상 측정[1], 진동 및 응력 측정[2], 매질의 굴절률 측정[3], 회전각 측정[4] 등과 같은 많은 분야에 응용할 수 있다. 무아레 무늬는 발생 방법에 따라 그림자식과 영사식으로 나뉘며, 영사식은 격자를 측정면에 투영시키는 방법으로 그림자식과 비교하여 격자보다 상대적으로 큰 물체도 측정할 수 있다. (중략)

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Fringe Sensitivity of Projection Moire Topography Due to Position of Light Source and Object Distance According to Grating Periods (영사식 무아레 토포그래피에서 격자 주기에 따른 물체거리와 광원의 위치에 대한 무늬 민감도 변화)

  • Oh, Hyun Seock;Ju, Yun Jae;Jo, Jae Heung
    • Korean Journal of Optics and Photonics
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    • v.27 no.2
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    • pp.67-72
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    • 2016
  • In projection moire topography, the investigation of fringe sensitivity, which means the change rate of fringe order according to object height, is important and necessary to reduce the measurement error of the shape of an object. Using the fringe sensitivity, the determination of the absolute orders of moire fringes can be performed very easily and rapidly. The important parameters in the determination of absolute orders of fringes are the positions of light source and object, and the grating period in projection moire topography. Among these parameters, the fringe sensitivity due to the transverse motion of the light source and the longitudinal motion of the object according to grating periods are analyzed and compared. As a result, whereas the fringe sensitivity in the transverse-motion method increases linearly and gradually as the distance between light source and imaging sensor increases, the fringe sensitivity due to the longitudinal-motion method decreases dramatically as the distance between imaging lens and object increases. In these methods, the fringe sensitivity and its change increase as the grating period increases.

A Scheme of User Face Recognition using a Moire Phenomenon in IoT Environment (IoT환경에서 무아레 현상을 이용한 사용자 얼굴 인증 기법)

  • Cho, Ik-Hyun;Lee, Keun-Ho
    • Journal of Digital Convergence
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    • v.17 no.2
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    • pp.171-176
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    • 2019
  • In modern times, many IoT products are being used as all things and devices are connected to the Internet and IoT products become easily accessible through the network. For the convenience of users, IoT products can be remotely operated automatically without manual operation. Various research and development are underway to improve the convenience of users by using IoT products. However, since only the convenience of the users is pursued, in terms of security, there is a serious problem that exposes the user's personal information. This paper has proposed a method to apply $moir{\acute{e}}$ technology to IoT products in order to improve the performance of security, and a method to increase the safety of IoT products using user face authentication based on shadow $moir{\acute{e}}$ as a $moir{\acute{e}}$ phenomenon method, and the projection $moir{\acute{e}}$. When comparing the existing IoT products and IoT products applied with $moir{\acute{e}}$ technology, IoT products applied with $moir{\acute{e}}$ technology are safer in terms of security.

A Proposal for Improvement of Detection of User Based on Facial Authentication Using Digital Projection Moire (디지털 영사식 무아레를 이용한 얼굴 인증 기반 출입자 탐지 개선 방법 제안)

  • Seo, Cho-Rong;Lee, Jeong-Pil;Lee, Keun-Ho;Jeon, You-Boo;Park, JinSoo
    • Proceedings of the Korea Information Processing Society Conference
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    • 2017.04a
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    • pp.366-367
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    • 2017
  • 생체인식 기술의 발달에 의해 생체 인증 수단 또한 늘어남에 따라 사용자의 얼굴을 이용한 인증방법이 점차 실용화 되어가고 있다. 그러나 주변 환경에 제약받을 경우 완벽한 인식률을 보여주지 못하는 경우가 발생한다. 본 논문에서는 기존의 얼굴인식 방법의 오탐지 부분에 대한 개선방법을 제안 하고자 하였다. 디지털 영사식 방법을 통한 무아레 현상을 얼굴인증에 접목시켜 보다 정확한 얼굴 인증을 진행할 수 있도록 개선된 인증 방법을 제시한다.

A Study on the Virtual Grating Projection Moire Topography for the Shape Measurement of Human Face (인체형상 측정을 위한 가상격자 영사식 무아레 방법에 관한 연구)

  • 유원재;최정표;안중근;강영준
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.49-52
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    • 2001
  • 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 projection moire topogrphy 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 $2\pi$-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding absolute fringe orders, so that the $2\pi$-ambiguity problem can be effectively overcome so as to treat large step discontinuities in measured objects.

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A Study on 3-D Shape Measurement and Application by using Digital Projection $Moir\acute{e}$ ( I ) (디지털 영사식 무아레를 이용한 3차원 형상 측정과 응용에 관한 연구( I ))

  • Ryu Weon-Jae;Rho Hyung-Min;Lee Dong-Hwan;Kang Young-June
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.7 s.172
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    • pp.88-93
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    • 2005
  • $Moir\acute{e}$ topography method is a well-known non-contacting 3-D measurement method. Recently, the automatic 3-D measurement by $Moir\acute{e}$ topography has been required, since the method was frequently applied to the engineering and medical fields. The 3-D measurement using projection $Moir\acute{e}$ topography is very attractive because of its high measuring speed and high sensitivity. In this paper, using two-wavelength method of projection $Moir\acute{e}$ topography was tested to measuring object with $2\pi-ambiguity$ problems. The experimental results prove that the proposed scheme is capable of finding absolute fringe orders, so that the $2\pi-ambiguity$ problems can be effectively overcome so as to treat large step discontinuities in measured objects.

A Study on 3-D Shape Measurement and Application by Using Digital Projection Moire (II) (디지털 영사식 무아레를 이용한 3차원 형상 측정과 응용에 관한 연구(II))

  • Ryu, Weon-Jae;Kang, Young-June;Rho, Hyung-Min;Lee, Dong-Hwan
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.5
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    • pp.62-67
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    • 2007
  • A simple dimension measuring method for the measurement of human bust has been developed using projection moire. The 3-D data of a human bust was calculated from the 2dimensional image information obtained by the stripe using projection moire. The creation of 3-D geometric shape by digitizing real objects has been widely investigated in reverse engineering(RE). This procedure generally consists of three basic steps: data capture, data alignment and model reconstruction. In order to achieve a complete model, multiple scans must be taken and aligned.