• 대한지리학회지
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• 제38권5호
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• pp.822-834
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• 2003

오늘날의 지형경관변화 분석은 그 규모와 시공간적 제한으로 말미암아 과거와 같이 연구자의 직접적인 참여관찰에 의해 취득된 정보만으로는 많은 한계를 가지게 된다. 이에 본 연구에서는 위성영상을 이용하여 직접적인 참여관찰이 어려운 해안습지 지역의 대규모 지형경관변화를 분석하는 방법들을 비교, 평가하는 것을 주목적으로 하였다. 연구지역은 지난 10년간 국제공항의 건설로 대규모 지형경관변화를 경험한 영종도 북부 해안습지를 사례지역으로 하였다. 분석방법은 기존의 마스크 기법을 보완한 화소차이 마스크 기법. 화소표준화 마스크 기법, NDVI 마스크 기법을 이용하였다. 분석결과 해안습지의 지형경관변화를 구체적이고 정확하게 반영하는 기법은 NDVI 마스크 기법인 것으로 판단되었다.

• 반도체디스플레이기술학회지
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• 제15권2호
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• pp.32-37
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• 2016

Sidewall angle (SWA) of an absorber stack in extreme ultraviolet lithography mask is considered to be $90^{\circ}$ ideally, however, it is difficult to obtain $90^{\circ}$ SWA because absorber profile is changed by complicated etching process. As the imaging performance of the mask can be varied with this SWA of the absorber stack, more complicated optical proximity correction is required to compensate for the variation of imaging performance. In this study, phase shift mask (PSM) is suggested to reduce the variation of imaging performance due to SWA change by modifying mask material and structure. Variations of imaging performance and lithography process margin depending on SWA were evaluated through aerial image and developed resist simulations to confirm the advantages of PSM over the binary intensity mask (BIM). The results show that the variations of normalized image log slope and critical dimension bias depending on SWA are reduced with PSM compared to BIM. Process margin for exposure dose and focus was also improved with PSM.

• 반도체디스플레이기술학회지
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• 제15권3호
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• pp.1-5
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• 2016

In order to apply sub-resolution assist feature (SRAF) in extreme ultraviolet lithography, the maximum non-printing SRAF width and lithography process margin needs to be improved. Through simulation, we confirmed that the maximum SRAF width of 6% attenuated phase shift mask (PSM) is large compared to conventional binary intensity mask. The increase in SRAF width is due to dark region's reflectivity of PSM which consequently improves the process window. Furthermore, the critical dimension error caused by variation of SRAF width and center position is reduced by lower change in diffraction amplitude. Therefore, we speculate that the margin of SRAF application will be improved by using PSM.

• 천문학논총
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• 제32권1호
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• pp.347-349
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• 2017

This paper reviews the legacy of the SPCIA Coronagraph Instrument (SCI) of which the primary scientific objective is the characterization of Jovian exoplanets by coronagraphic spectroscopy in the infrared. Studies on binary shaped pupil mask coronagraphs are described. Cryogenic active optics is discussed as another key technology. Then approaches to observing habitable zones in exoplanetary systems with a passively-cooled space infrared telescope are discussed. The SCI was dropped in a drastic change of the SPICA mission. However, its legacy is useful for space-borne infrared telescopes dedicated for use in exoplanetary science in the future, especially for studies of biomarkers.