• Journal of the Korean Society for Precision Engineering
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• v.27 no.4
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• pp.102-108
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• 2010

Projection microstereolithography is a process of fabricating a micro-structure by using dynamic mask such as digital micromirror device(DMD). DMD shapes the beam into cross-sectional image of structure. Photocurable resin is cured by the beam and stacked layer on top of layer. It is difficult to deliver the beam from the DMD to the photocurable resin without any distortions. We assume that the beam exposed to the resin by 1 pixel of DMD has Gaussian distribution, so the shaped beam reflected by the DMD affects its neighboring area. Curing pattern corresponding to a cross-sectional images is predicted by superposition of pixels of Gaussian distribution and it is similar to cured shape.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1253-1256
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• 2005

We have developed an electron lithography method, Electron Emission Lithography (EEL), which is capable of printing integrated circuits with an exposure time of only a few seconds. The basic design of the mask, manufactured by standard MIM technology, will be discussed. Patterns printed into e-beam resist by a 1:1 projection system show the applicability of the mask for lithography purposes. The minimum feature size projected so far is 10 um in a system capable of 100 m resolution. Further improvements in resolution to 50 nm are possible.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.197-203
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• 2004

New lithography techniques are employed for the patterning of arbitrary shapes in nanometer scale. When, in the photolithography, the electromagnetic waves such as UV and X-ray are incident on the mask patterned in nanometer scale, the diffraction effect is unavoidable and degrades images of the mask imprinted on wafer. Only a convex lens is well-known Fourier transformer. It is possible to make the mask Fourier-transformed with the convex lens, even though the size of pattern on the mask is very large compared to the wavelength of electromagnetic wave. If the mask, modified according to new technique described in this paper, was placed at the front of the lens and was illuminated with laser beam, the nanometer-size patterns are only formed on the plane called Fourier transform plane. The new method presented here is quite simple setup and comparable with present and next generation lithographies such as UV/EUV photolithograpy and electron projection lithography when compared in attainable minimum linewidth. In this paper, we showed our theoretical research work in the field of Fourier optics, . In the near future, we are going to verify this theoretical work by experiments.

• Solar Energy
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• v.19 no.2
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• pp.9-19
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• 1999

For determining solar benefit hour are two different methods required as a direct calculation which is more accurate but too slow, and a computer graphic protration which is less accurate but too fast. To have the later accurate, the hour to hour interpolation is used to provide less visual deviation. With directly pointing the solar location into the screen coordinate the waldram projection and stereographic projection which needs the number of fast algorithms to calculate the coordinates of the sun path and building configuration casting to the space are applied.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.4
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• pp.39-43
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• 1985

The charcterization of optical lithography on the step and repeat projection system is studied. Parameters that influence optical lithography were analyzed and the experiment was performed on the mask of $\pm$ 5rm, the surface flatness. From the experiment, the relationship between linewidth diviation on defocus and linewidth shift on exposure of the small features is obtained. Conditions maintaining good uniformity of small features from these relation-ships is presented.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.670-672
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• 2002

본 논문에서는 잘못된 인쇄로 인한 문서상의 잡영이나 문자 훼손이 있는 문서를 복원 하고자 만다. 제안하는 방법은 스캐너로 읽어들인 문서영상을 잡영 제거론 만 다음 훼손된 숫자 영상에 대해서 프로젝션을 이용하여 숫자 열을 낱낱의 숫자로 분할한다. 각각의 숫자에 대해서 크기가 일정하도록 정규화를 시킨 다음, Backpropagalion을 이용하여 훼손된 숫자를 학습하였다. 학습시킨 다음 원 영상과 훼손된 영상을 각 픽셀단위로 비교하여 4-방향 마스크를 이용하여 원래의 숫자 영상으로 복원하도록 만다.

• Journal of the Korean Graphic Arts Communication Society
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• v.3 no.1
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• pp.27-41
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• 1985

Following results about Y,M,C mask are obtained by the Indirect-Screen Color Separation Method. We make use of experimental systems which are in use for the student education. In the Camera-back Method of reflection copy, the results are summerized as follows; In the projection Method of transparency copy, the results are summerized as follows; Table moitted.

• Korean Journal of Optics and Photonics
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• v.20 no.3
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• pp.175-181
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• 2009

Holographic lithography is one of the potential technologies for next generation lithography which can print large areas (6") as well as very fine patterns ($0.35{\mu}m$). Usually, photolithography has been developed with two target purposes. One was for LCD applications which require large areas (over 6") and micro pattern (over $1.5{\mu}m$) exposure. The other was for semiconductor applications which require small areas (1.5") and nano pattern (under $0.2{\mu}m$) exposure. However, holographic lithography can print fine patterns from $0.35{\mu}m$ to $1.5{\mu}m$ keeping the exposure area inside 6". This is one of the great advantages in order to realize high speed fine pattern photolithography. How? It is because holographic lithography is taking holographic optics instead of projection optics. A hologram mask is the key component of holographic optics, which can perform the same function as projection optics. In this paper, Surface-Relief TIR Hologram Mask technology is introduced, and enables more robust hologram masks than those previously reported that were formed in photopolymer recording materials. We describe the important parameters in the fabrication process and their optimization, and we evaluate the patterns printed from the surface-relief TIR hologram masks.

• Journal of Biomedical Engineering Research
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• v.20 no.2
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• pp.155-164
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• 1999

In this paper, the prototype of SIS(Simulated Implantation System) for human femoral head is introduced. SIS is a software which carries on a virtual femoral head replacement surgery including 3d visualization as well as various numeric analyses between a patient's femur and artificial femur through certain stages of the image processing and of the computer graphics. Also, processes required after acquiring consecutive CT-images and projected image of an artificial femur are discussed, and the corresponding results including prototype of SIS are given.

• The Journal of the Korea Contents Association
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• v.3 no.4
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• pp.23-28
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• 2003

This paper describes, in order to extract contour from topographic map image, an adaptive segment-length thresholding using a threshold depended on target image. First of all, after recognizing the primary symbols and detecting two edges from the projection histogram of the elevation value area, the threshold value is determined by the distance between the edges. Then, the subdivision is peformed by searching a branch point and erasing its neighboring Hack pixels. And contour components are extracted by segment-length thresholding. The experimental result shows that the final image contains non-contour component of 2.41% and contour one of 97.59%.