• 한국광학회:학술대회논문집
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• 한국광학회 1995년도 광학 및 양자전자학 워크샵 논문집
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• pp.59-67
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• 1995

부분간섭조명과 central obscuration의 Optical Transfer Function(OTF) 에의 영향을 조사해보고, 이의 programing 기법을 소개하며, 모든 3차 수차와 5차 구면수차가 제거된 5반사광학계에 적용하여 축소배율(M = +1/5)을 갖는 리소그래피용 광학계로서의 가능성을 알아보았다. 이렇게 하여 얻어진 광학계 central obscuration이 약 31%이고 과월을 ArF excimer 레이저( 파장 0.193$\mu$m) 로 하는 nearly inchorent illumination($\sigma$ = 1.0)인 경우 NA가 0.45이며 분해능이 50% MTF 기준치와 초점심도 0.8$\mu$m에 대해 약 600cycles/mm 정도인 성능을 갖는 시스템이 되었다.

• 한국화재소방학회논문지
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• 제15권3호
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• pp.1-6
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• 2001

옥내화재에서 높이에 따른 암흑화의 정도를, 본 연구를 목적으로 제작된 스모크박스를 이용한 실험을 통해 측정하였다. 연기로 인한 암흑화의 정도는 높이에 따라서 결정되는데, 높은 곳일수록 그 정도가 심했다. 그러나 급기구가 있는 높이에서는 암흑화가 심해지는 변이가 일어났다.

• 한국광학회지
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• 제5권1호
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• pp.1-8
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• 1994

축소배율(M=+1/5)을 갖는 극자외선(deep dultra-violet)리소그라피용 5-반사광학계를 설계하였다. 우선 모든 3차 수치를 영으로 하는 수치적인 해를 반사경이 구면인 경우에 대해서 구하였다. 이렇게 하여 구한 3차원적인 분포를 하는 해의 영역에서 잔류수차량과 MTF에 큰 영향을 주는 central obscuration이 될 수 있는 한 적은 해들을 선택하여 마지막 두 반사경을 비구면화 하였다. 이 중 최종적인 해로서 선택한 것은 central obscuration이 약 25%이고 광원을 ArF 엑시머 레이저(파장 0.193 ${\mu}m$)로 하는 nearly inchorent illumination(${\sigma}$=1)인 경우 NA가 0.45이며 분해능이 50% MTF 기준치와 초점심도 0.8 ${\mu}m$에 대해 약 650 cycles/mm 정도인 성능을 갖는 시스템이 되었다.

• 대한기계학회논문집B
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• 제39권12호
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• pp.935-943
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• 2015

본 논문에서는 풍력발전기 나셀 내부의 화재 조기감지 및 화재발생위치를 판단하는 방법을 제안한다. 화재감지 변수로는 온도와 공기 혼탁도 상승률을 이용하는데, 이것은 온도와 혼탁도의 절대 값과 상관이 없이 화재를 감지할 수 있기 때문에 비화재보를 최소화 할 수 있는 방법이다. 화재발생위치는 다수의 화재감지 센서들의 거리에 따른 화재감지 시간차를 이용하였다. 또한 다양한 실험을 통하여 개발된 방법의 성능을 테스트하였다.

• 한국항공운항학회지
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• 제13권4호
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• pp.1-10
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• 2005

According to the aviational definition, the fog is an obscuration phenomenon when prevailing visibility becomes less than 1,000m. Fog defined above causes so many aviation traffic problems like detour, flight delay and cancel. Therefore this study investigated quantitatively the fog effects on flight operation using flight delay and cancel statistic data during last four years from 1st Jul. 2001 to 30th Jun. 2005 at the Incheon Int'l Airport. The results of this study show that the hazardous meteorological condition is a important cause of flight delay and cancel, especially fog phenomenon. And it is expected that the results of this study give us the necessary and importance of fog prediction at the Incheon Int'l Airport.

• 천문학회보
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• 제35권2호
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• pp.32.2-32.2
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• 2010

Red dusty Active Galactic Nuclei (AGNs) are suspected to mid-stage between ULIRG and AGN phase. As well as, they are suspected that they have more than 50% of AGN population. To understand character of red AGN, Black Hole (BH) mass of red AGN is a key property and haven't measured by existing method such as reverberation mapping and single epoch method. So we still don't know their character and properties clearly. To estimate properties of red AGNs escape from effect of dust-obscuration, we have obtained Near InfraRed (NIR) spectra of 31 reverberation mapped AGNs and 49 Palomar-Green(PG) Quasi-Stellar Object (QSO) using the infrared camera (IRC) for AKARI with unique wavelength range 2.5-$5.0{\mu}m$. From this spectra, we measured the FWHM and luminosity of brackett ${\alpha}$, ${\beta}$ at 4.0, 2.6 micron meter for deriving new BH mass estimators based on the properties of Brackett line emission.

• 천문학회보
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• 제43권1호
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• pp.37.2-37.2
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• 2018

The Wide-field Infrared Survey Explorer (WISE) mission has been efficient in selecting Active Galactic Nuclei (AGN) with high luminosities and large obscuration. According to the merger driven AGN powering scenarios, luminous and obscured AGN are in a stage where they go through feeding of gas accretion into the central black hole, and feedback to the host galaxy through outflows. We report the rest-frame UV-optical spectra of 11 Hot Dust Obscured Galaxies (Hot DOGs) at z~2, WISE color-selected to be extremely reddened AGN. A fraction of the targets show blueshifted and broadened [OIII] profiles indicative of ionized gas outflows. We present the occurrence and strength of the outflows, and discuss what impact these AGN activity could give on their hosts.

• 천문학회보
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• 제36권1호
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• pp.51.1-51.1
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• 2011

Red dusty Active Galactic Nuclei (AGNs) are suspected to mid-stage between ULIRG and AGN phase. As well as, red AGNs are suspected that they have more than 50% of whole AGN population. In order to understand the character of red AGNs, Black Hole (BH) mass of red AGN is a key property and can not measured by existing method such as reverberation mapping and single epoch method. Thus we still don't know their character and properties in clearly. To estimate properties of red AGNs without the effect of dust-obscuration, we have obtained Near InfraRed (NIR) spectra of 31 reverberation mapped AGNs and 49 Palomar-Green(PG) Quasi-Stellar Object (QSO) by using the infrared camera (IRC) for AKARI with unique wavelength range $2.5-5.0{\mu}m$. From this spectra, we measured the FWHM and luminosity of brackett ${\alpha}$ and ${\beta}$ at 4.0, 2.6 micron meter for deriving new BH mass estimators based on the properties of Brackett line emission.

• 천문학회보
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• 제43권2호
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• pp.55.2-55.2
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• 2018

The Wide-field Infrared Survey Explorer (WISE) mission enabled efficient selection of Active Galactic Nuclei (AGN) with high luminosities and large obscuration. According to the merger driven AGN powering scenarios, luminous and obscured AGN are in a stage where they go through feeding of gas accretion into the central black hole, and feedback to the host galaxy through outflows. We report the rest-frame UV-optical spectra of Hot Dust Obscured Galaxies (Hot DOGs) at z~2, WISE color-selected to be extremely reddened AGN. Most of the targets show blueshifted and broadened [OIII] line profiles indicative of ionized gas outflows. We present the occurrence and strength of the outflows, and discuss the impact of luminous, obscured AGN activity on their hosts.

• 천문학회보
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• 제45권1호
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• pp.67.3-68
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• 2020

A prime focus telescope, e.g., Schmidt telescope, has advantages especially for a wide field of view survey in astronomy. In this optical configuration, the camera is placed in front of the primary mirror. Since the installation of a typical filter wheel to the prime focus telescope causes serious obscuration of the incoming light, a customized filter device is required for high sensitivity images. In this poster, we present a new filter exchange mechanism, which can host four filters moving along quadrant directions. We plan to install this on the Celestron 36 cm Rowe-Ackermann Schmidt Astrograph (RASA 36) located at El Sause Observatory in Chile.