• 천문학회보
• /
• 제40권1호
• /
• pp.86.4-87
• /
• 2015

We will soon complete the installation of 1m telescope at Deokheung Optical Astronomy Observatory (DOAO), National Youth Space Center (NYSC). Before the test observation with NYSC 1m telescope, we present the specs of the 1M telescope and observational conditions of the DOAO site, such as the seeing data at DOAO and the atmospheric extinction coefficients obtained from the observations of standard stars and stellar clusters with 120mm and 150mm refractor in 2014. Since atmospheric extinction coefficients depend on the observational instruments as well as the atmospheric conditions of the site, the improved data with NYSC 1m telescope will be obtained right after the completion of 1M telescope installation. We are planning to invite all astronomers to use 1m telescope for their sciences via regular proposal processes in this year.

• 천문학회지
• /
• 제29권spc1호
• /
• pp.415-418
• /
• 1996

Space Solar Telescope (SST) is a space project for solar research, its main parameters are that total weight 2.0T, sun synchronous polar circular orbit, altitude of the orbit 730KM, 3 axis stabilized attitude system, power 1200W, telemetry of the downlink rate 30Mb/s, size $5{\ast}2{\ast}2\;M^3$, mission life 3 years. It is expected it will be launched in 2001 or later. The main objective is structure and evolution of solar vector magnetic field with very high spatial resolution. The payloads are consisted of 6 instruments: Main optical telescope with 1-M diameter and diffraction limited resolution 0.1 arc second, EUV imaging telescope with a bundle of four telescopes and 0.5 arc second resolution, spectrometric optical coronagraph, wide band spectrometer, H-alpha and white light telescope and solar and interplanetary radiospectrometer. An assessment study between China and Germany is under operation.

• 한국가시화정보학회지
• /
• 제10권2호
• /
• pp.25-31
• /
• 2012

High-performance smartphones, equipped with a digital camera and an application software, can render conventional bench-top laboratory instruments mobile at affordable costs. As the smartphone-based devices are portable and wireless, they have wide applications especially in providing point-of-care (POC) tests in resource-constrained areas. We developed a hand-held diagnostic system, Mobile SmartScope, which consists of a small optical unit integrated with a smartphone. The performance of the SmartScope was favorably compared with that of conventional light microscopy in detecting and quantifying red blood cells. We also evaluated the fluorescence detection limit of the SmartScope incorporated with a blue light-emitting diode and appropriate optical filters by using fluorescently labeled microbeads for intensity calibration.

• International Journal of Precision Engineering and Manufacturing
• /
• 제1권2호
• /
• pp.115-123
• /
• 2000

We propose an extended version of multi-step algorithm of self-calibration of interferometric optical testing instruments. The key idea is to take wavefront measurements with near equal steps in that a slight angular offset is intentionally provided in part rotation. This generalized algorithm adopts least squares technique to determine the true azimuthal positions of part rotation and consequently eliminates calibration errors caused by rotation inaccuracy. In addition, the required numbers of part rotation is greatly reduced when higher order spatial frequency terms are of particular importance.

• 한국통신학회논문지
• /
• 제14권4호
• /
• pp.307-320
• /
• 1989

본 논문은 모재 제작을 위한 Modified Chemical Vapor Deposition(MCVD) 장치의 새로운 설계를 제안하였다. MCVD 공정의 기본 장치로는 선반장치와 원료가스공급 장치가 포함되고, 언덕형 광섬유 설계, 공정의 특성 및 MCVD 모재의 굴정율 형태를 측정하는 실험장치를 각기 실현하였다. 연구결과, 중심부 딥(dip)이나 범프(bump) 가 보이지 않는 이상적 언덕형 굴절율 광섬유 모재를 얻었다.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
• /
• pp.302-305
• /
• 2007

During the CareBeijing campaign in September 2006, Imaging Differential Optical Absorption Spectroscopy (IDOAS) measurements were made over the city of Beijing, China using a spatial resolution of 146 pixels horizontally and 61 pixels vertically, each with a field of view of $0.133^{\circ}$ and $0.072^{\circ}$ in the horizontal and vertical directions, respectively. Using Fraunhofer reference spectra (FRS) for the evaluation of data for two consecutive days, the diurnal variation of $NO_2$ distributions was determined from data measured every single hour from 08:00 until 16:00 on September 9 and 10. Both days presented a fairly clear sky with high visibility. The setup allowed detailed images of the low surface $NO_2$ distribution over Beijing. Images with less than a 30-min temporal resolution showed variation of plume dispersal in both horizontal and vertical directions. An in-situ measurement was also conducted. Results from both instruments are interpreted by considering local emission sources and wind conditions.

• 한국광학회지
• /
• 제16권5호
• /
• pp.433-439
• /
• 2005

백색 광원과 컬러 센서를 이용하여 바이오 센서의 발색 정도를 측정하는 측정기를 개발하였다. 컬러 센서의 적색, 녹색 및 청색영역의 빛의 세기를 비율로 나타냄으로서, 조사 광의 세기가 변하는 경우에도 안정적인 분광 정보를 얻을 수가 있었고, 바이오 센서의 화학적 처리 과정에서 발생하는 수막 등의 영향에 의한 오차를 감소시킬 수 있다. 바이오 센서의 발색 변화율이 작은 경우 컬러 센서의 각 영역에 대한 증폭률을 조정하는 것만으로 시스템의 민감도를 향상 시킬 수 있었다.

• 천문학회보
• /
• 제44권2호
• /
• pp.47.1-47.1
• /
• 2019

We report the design and vibration analysis for the optomechanical structures of Linear Astigmatism Free - Three Mirror System (LAF-TMS). LAF-TMS is the linear astigmatism free off-axis wide-field telescope with D = 150 mm, F/3.3, and FOV = 5.51° × 4.13°. The whole structure consists of four optomechanical modules. It can accurately mount mirrors and also can survive from vibration environments. The Mass Acceleration Curve (MAC) is adapted to the quasi-static analysis. Modal, harmonic, and random vibration analysis have been performed under the qualification level of the launch system. We evaluate the final results in terms of von Mises stress and Margin of Safety (MoS).

• 천문학회보
• /
• 제36권1호
• /
• pp.27.2-27.2
• /
• 2011

The Kepler(NASA) and CoRoT(ESA) space telescopes are surveying thousands of exoplanet for finding Earth-like exoplanets with similar environments of the Earth. Then the TPF(NASA), DARWIN(ESA) and many large-aperture ground telescopes have plan for spectroscopic observations of these earth-like exoplanets in next decades. Now, it has been started to simulate the disk averaged spectra of the earthlike exoplanets for comparing the observed spectra and suggesting solutions of environment of these planets. Previous research, the simulations are based on radiative transfer method, but these are limited by optical models of Earth system and instruments. We introduce a new simulation method, IRT(Integrated Ray Tracing) to overcome limitations of previous method. The 3 components are defined in IRT; 1)Sun model, 2)Earth system model (Atmosphere, Land and Ocean), 3)Instrument model. The ray tracing in IRT is simulated in composed 3D real scale space from inside the sun model to the detector of instrument. The Sun model has hemisphere structure with Lambertian scattering optical model. Atmosphere is composed of 16 distributed structures and each optical model includes BSDF with using 6SV radiative transfer code. Coastline and 5 kinds of vegetation distribution data are used to land model structure, and its non-Lambertian scattering optical model is defined with the semi-empirical "parametric kernel method" used for MODIS(NASA) and POLDER(CNES) missions. The ocean model includes sea ice cap structure with the monthly sea ice area variation, and sea water optical model which is considering non-lambertian sun-glint scattering. Computation of spectral imaging and radiative transfer performance of Earth system model is tested with hypothetical space instrument in IRT model. Then we calculated the disk averaged spectra of the Earth system model in IRT computation model for 8 cases; 4 viewing orientation cases with full illuminated phase, and 4 illuminated phase cases in a viewing orientation. Finally the DAS results are compared with previous researching results of radiative transfer method.

• 센서학회지
• /
• 제10권1호
• /
• pp.42-51
• /
• 2001

본 연구에서는 복합재료에 삽입된 광섬유센서의 인장하중하에서의 정적 물성치와 피로하중하에서의 동적 물성치를 실험적인 방법과 유한요소해석을 통하여 고찰하였다. 결과에 의하면 삽입된 광섬유센서는 인접한 강화섬유에 수직한 방향으로 삽입된 피로하중의 경우를 제외하고 복합재료의 기계적인 물성치에 큰 영향을 끼치지 않는다고 결론지을 수 있다. 광강도형 광섬유센서를 복합재료 적층판에 삽입하여 복합재 적층판의 강성저하를 측정함으로써 직교적층판 피로손상을 검출하였다. 이 실험의 결과에 의하면 광강도형 광섬유센서는 간단하고 저렴한 장치와 측정된 신호의 복잡한 후처리 과정이 필요 없다는 장점으로 인하여 구조물의 강성저하를 측정하여 피로손상을 감시하는데 있어서 큰 잠재력을 가진다고 할 수 있다. 또한 삽입된 광강도형 광섬유센서는 우수한 내 피로성과 넓은 강성측정 범위를 보였다.