• 제목/요약/키워드: 정밀 격자

검색결과 294건 처리시간 0.305초

Development of Temperature Measurement System Using Fiber Optics Linear Transmittance Filter with Fiber Bragg Grading Sensor (FBG 센서와 LTOF 를 이용한 온도측정시스템 개발)

  • Nam, Kwang Sik;Choi, Jin Gyu;Zhao, Shang;Kim, Jea Ki;Choi, Ho Min;Lee, Seok Soon
    • Journal of the Korean Society for Precision Engineering
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    • 제33권4호
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    • pp.303-307
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    • 2016
  • The fiber optical temperature sensing device was developed by using a Fiber Bragg Grading (FBG) sensor and a linear transmittance optical filter. The temperature change causes change in the FBG sensor reflectance wavelength and the reflectance wavelength from FBG sensor is transmitted to a linear transmittance filter so that the optical signal value is determined by the wavelength. The temperature can be measured by the optical signal value by passing FBG reflectance wavelength to the linear transmittance filter. Using the developed system, temperature ranges from $10^{\circ}C$ to $50^{\circ}C$ were measured and the measured data were almost linear.

Finite Element Analysis of Two-Dimensional Cold Forging By Using Modular Remeshing and Expert System (단위체 격자 재구성법과 전문가 시스템을 이용한 2차원 냉간 단조의 유한 요소 해석)

  • Yun, Hui-Do;Kim, Yeong-Tae;Lee, Nak-Gyu;Yang, Dong-Yeol;Lee, Byeong-Chae
    • Journal of the Korean Society for Precision Engineering
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    • 제9권3호
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    • pp.83-101
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    • 1992
  • A systematic method of remeshing is required due to severe mesh distortion after some finite deformation in the finite element analysis of practical forging processes. In order to cope with the problem of mesh degeneracy during deformation, the proper design of meshes plays an improtant role in the analysis. In so-called "Modular Remeshing", the physical characteristics of metal flow and geometric characteristics are incorporated in "Module", which can be applied to the mesh design for a certain mode of deformation in so far as the topology of deforming region remains the same. For the purpose of more effective and systematic use of the modular remeshing scheme, an expert system has been developed in the framework of the proposed remeshing schemel. In oredr to show the effectiveness of the method, the rib-web type forging with axial relief or radial relief and spike forging are simulated. It has been thus shown that the proposed method of automatic remeshing by using modular remeshing and expert system can be futher extended and applied to various forging problems with complicated geometrical configurations.ical configurations.

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A Study on Projective Calibration for Arbitrary Display Surface using Digital Moire Method. (Digital Moire를 이용한 임의의 영사면에 대한 투영보정에 관한 연구)

  • 유원재;김도훈;강영준;백성훈
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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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

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Earthwork Plan Using the Precise 3D Topographic Data (3차원 정밀지형자료를 활용한 토공계획 개선)

  • Lee, Jin-Nyoung;Pyeon, Mu-Wook;Koo, Jee-Hee;Park, Jae-Sun
    • Journal of Korean Society for Geospatial Information Science
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    • 제18권1호
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    • pp.63-72
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    • 2010
  • In this study, an earth work design program which will improve the efficiency of earth work and enable to carry out the design using 3D Geospace-based earth work modelling in design stage was developed. Estimate of accurate earth work volume is achievable using 3D grid DEM, and based on this, a mass calculation chart was developed for movement of earth and equipment. In consideration for the resources for various construction equipments needed for civil engineering works, soil conversion and the passage is displayed. In addition, the result is restored in the form of open API-based KLM to make it possible for the users to identify the progress of the construction, thereby enhancing the intuitive understanding of three-dimensional visualization and making it easier to share the result of the analysis.

Study and Fabrication of Transparent Electrode Film by using Thermal-Roll Imprinted Ag Mesh Pattern and Coated Conductive Polymer (열형-롤 각인으로 형성한 Ag 격자 패턴과 전도성 고분자 코팅을 이용한 투명전극 필름 제작에 관한 연구)

  • Yu, Jong-Su;Jo, Jeong-Dai;Yoon, Seong-Man;Kim, Do-Jin
    • Journal of the Korean Society for Precision Engineering
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    • 제27권9호
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    • pp.11-15
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    • 2010
  • In this study, to fabricate a low-resistance and high optical transparency electrode film, the following steps were performed: the design and manufacture of electroforming stamp, the fabrication of a thermal roll-imprinted polycarbonate (PC) patterned films, the filled low-resistance Ag paste using doctor blade process on patterned PC films and spin coating by conductive polymers. As a result of PC films imprinted line width of $26.69{\pm}2\;{\mu}m$, channel length of $247.57{\pm}2\;{\mu}m$, and pattern depth of $7.54{\pm}0.2\;{\mu}m$. Ag paste to fill part of the patterned film with conductive polymer coating and then the following parameters were obtained: a sheet resistance of $11.1\;{\Omega}/sq$ optical transparency values at a wavelength of 550 nm was 80.31 %.

Practical application of picosecond laser micro-machining to the direct fabrication of a diffraction grating mold (피코초 레이저를 이용한 회절 격자 금형 개발)

  • Noh Ji-Whan;Lee Jae-Hoon;Sohn Hyon-Kee;Suh Jeong;Shin Dong-Sig
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.487-488
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    • 2006
  • Picosecond (ps) laser micro-machining has emerged as an attractive method of fabricating high-precision microstructures, especially in metals. In this paper, a metallic mold for diffraction gratings is fabricated with a mode-locked 12 Ps $Nd:YVO_4$ laser. Laser pulses with a wavelength of 355nm are irradiated on the surface of NOK 80, a mold material, to generate line patterns. In order to minimize the line width, laser power is set just above the ablation threshold of NOK 80. Results show that the spectrum from the fabricated mold is good enough for some industrial application.

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A Coarse Mesh Model for Numerical Analysis of Lead Frame Deformation Due to Blanking Residual Stress (블랭킹 잔류응력에 의한 리드프레임 변형 수치해석을 위한 대격자 모델)

  • Kim Yong Yun
    • Journal of the Korean Society for Precision Engineering
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    • 제22권2호
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    • pp.133-138
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    • 2005
  • The deformation of sheet metal due to the residual stress during blanking or piercing process, is numerically simulated by means of a commercial finite element code. Two dimensional plain strain problem is solved and then its result is applied to the deformation analysis of the lead frame. The plain strain element is applied to the 2D problem to observe the Von Mises equivalent stress concentration at the both shearing edges. As the punch penetrates into the sheet material, the stress concentration generated on both edges is getting increased to be the shearing surface. The limits of the punching depth applied to the simulation is 16% and 24% of the sheet thickness for the plain strain element and the hexahedral element, respectively. The hexahedral element and the limit of punching depth were applied to the deformation analysis of the lead frame for the blanking process. The FEM results for the lead deformation were very good agreement with the experimental ones. This paper shows that the coarse mesh has enabled to analyze the lead deformation generated due to the blanking mechanism. This simple approach to save the calculation time will be very effective to the design of the blanking tools in industries.

A Study on the Improvement of Accuracy of Surface Measurement in the Phase-Shifting Shadow Moir$\'{e}$ Method (위상이동 그림자 무아레방법을 이용한 형상측정법의 정확도 개선에 관한 연구)

  • 강영준;유원재;권용기
    • Journal of the Korean Society for Precision Engineering
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    • 제15권10호
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    • pp.96-102
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    • 1998
  • In this study, the theory and application of phase-shifting shadow moire topography is focused on the non-contact measurement of object surfaces for practical use in the field of production engineering. Shadow moire topography has been studied during last few decades in the area of the optical physics, and now its mathmatical theory has been established. Generally, in case of the classical shadow moire topography, the sensitivity is a few tenths of millimeter in best cases. Here we tried the application of phase-shifting method to the conventional shadow moire topography. But the reference grating and the deformed grating are mutually dependent because it is impossible to obtain uniform phase shifts on the whole Held. Therefore it is difficult to use a phase-shifting method in shadow moire topography. However, it was shown that constant phase-shifting was able to be measured by moving both the grating and light source. Finally we obtained a better result by using this procedure and applied the phase-shifting shadow moire to three dimensional object measurement.

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Development of the Geoid Model in Korean Peninsula referred to Bessel Ellipsoid (베셀타원체상에서의 한반도 지오이드 모델의 개발)

  • 이석배
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • 제16권2호
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    • pp.213-223
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    • 1998
  • This paper deals with the geoid modelling in and around Korean peninsula referred to Bessel ellipsoid. Several useful data were used to compute precise geoidal heights referred to GRS80 by remove and restore technique and FFT technique was used to evaluate Stokes' integral. All grid point elevations extracted from GTOPO 30 and Bessel coordinates of all grid point were computed through coordinates transformation by applying three transformation parameters. Finally, geoidal heights referred to Bessel ellipsoid were calculated by geometric method. As the results of this study, a precise gravimetric geoid model referred to GRS80 (KOGGDM33) and geoid model referred to Bessel ellipsoid(KOBGDM33) in and around Korean peninsula were developed. KOBGDM33 shows the gradual distribution of geoidal heights from -91.8 m in Yongampo to -39.0 m in the straits of Korea.

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Fabrication of Silicon Angle Standard and Calibration of Rotary Encoder Using Silicon Angle Standard (각도교정용 실리콘 다면체의 제작과 이를 이용한 회전에코더의 각도교정)

  • 박진원;엄천일
    • Korean Journal of Crystallography
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    • 제6권2호
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    • pp.88-92
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    • 1995
  • Higly pure silicon crystals with an almost perfect lattice structure constityte a powerful metrological tool. The streographic standard prohection for the (111) orientation of diamond structure found by the Laue method shows angles between net planes of 60°. This value is known to be certain to some 10-8 rad. We have made a six-faced silicon polygon, and the (220) lattice planes of the polygon act as a reference angular standard. The information of angles between lattice planes could be taken by the X-ray diffraction. The angle of the rotary encoder have been calibrated using the silicon angle standard. The X-ray optics was double crystal arrangement.

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