A5101779666- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- Space Satellite Systems and Control
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Spacecraft Design and Technology
- Astronomical Observations and Instrumentation
- Chemical synthesis and alkaloids
- Ionosphere and magnetosphere dynamics
- Advanced Optical Sensing Technologies
- Synthetic Organic Chemistry Methods
- GNSS positioning and interference
- Food Quality and Safety Studies
- Astrophysics and Cosmic Phenomena
- Scientific Research and Discoveries
- Satellite Image Processing and Photogrammetry
- Marine Sponges and Natural Products
- Atmospheric Ozone and Climate
- Advanced optical system design
- Space exploration and regulation
- Advanced Vision and Imaging
- Optical Systems and Laser Technology
- Inertial Sensor and Navigation
Korea Astronomy and Space Science Institute
2009-2020
Seoul National University
2007-2008
Yonsei University
1995
We present a study on four new star clusters discovered in the halo of intriguing dwarf irregular galaxy NGC 6822 from wide-field survey covering 3° × area carried out with MegaCam at Canada–France–Hawaii Telescope. The have extended structures half-light radii Rh ≈ 7.5–14.0 pc, larger than typical Galactic globular and other known 6822. integrated colors color–magnitude diagrams resolved stars suggest that are 2–10 Gyr old relatively metal poor Z = 0.0001–0.004 based comparison theoretical...
Wide-field deep gri images obtained with the Megacam of Canada-France-Hawaii Telescope (CFHT) are used to investigate spatial configuration stars around five metal-poor globular cluster M15, M30, M53, NGC 5053, and 5466, in a field-of-view ~3 degree. Applying mask filtering algorithm color-magnitude diagrams observed stars, we sorted cluster's member star candidates that examine characteristics stellar distribution surrounding target clusters. The smoothed surface density maps overlaid...
Two analogs of sildenafil and vardenafil in food were detected by column liquid chromatography (LC) with a photodiode array detector. They isolated preparative LC; their structures established mass spectrometry nuclear magnetic resonance spectrometry. One analog was found to be methisosildenafil (compound A), 5-(5-(3,5-dimethylpiperazin-1-ylsulfonyl)-2-ethoxy-phenyl)-1-methyl-3-propyl-1H-pyrazolo[4,3-d]-pyrimidin-7(6H)-one. It is dimethylpiperazine ring substituted for the methylpiperazine...
The detector subsystem of the Optical Wide-field Patrol (OWL) network efficiently acquires position and time information moving objects such as artificial satellites through its chopper system, which consists 4 blades in front CCD camera. Using this it is possible to get more data with same exposure by changing streaks into many pieces fast rotating during sidereal tracking. At time, from can be acquired tagger connected photo diode. To analyze orbits targets detected image a sequential...
An Optical Wide-field patroL-Network (OWL-Net) has been developed for maintaining Korean low Earth orbit (LEO) satellites' orbital ephemeris. The OWL-Net consists of five optical tracking stations. Brightness signals reflected sunlight the targets were detected by a charged coupled device (CCD). A chopper system was adopted fast astrometric data sampling, maximum 50 Hz, within short observation time. accuracy validated with precise ephemeris such as Consolidated Prediction File (CPF) and...
Korea Astronomy and Space Science Institute (KASI) has developed a mobile satellite laser ranging (SLR) system called ARGO-M since 2008 for space geodesy research precise orbit determination technologies using SLR with mm level accuracy. is capable of night tracking daylight which requires spatial, spectral time filters due to high background noises. In this study, characteristics specifications are discussed its capabilities analyzed STSAT-2B KOMPSAT-5 through link budget. Additionally...
With increased human activity in space, the risk of re-entry and collision between space objects is constantly increasing. Hence, need for situational awareness (SSA) programs has been acknowledged by many experienced agencies. Optical radar sensors, which enable surveillance tracking objects, are most important technical components SSA systems. In particular, combinations systems optical sensor networks play an outstanding role programs. At present, Korea operates wide field patrol network...
We present SPEAR/FIMS far-ultraviolet observations near the north ecliptic pole. This area, at b ~ 30° and with intermediate H I column, seems to be a fairly typical line of sight that is representative general processes in diffuse interstellar medium. detect surprising number emission lines many elements various ionization states, representing gas phases from warm neutral medium hot ionized also fluorescence bands H2, which may due ubiquitous H2 previously observed absorption.
A compact infrared space telescope called MIRIS (Multi-purpose Infra-Red Imaging System) was developed by the Korea Astronomy and Space Science Institute (KASI), launched onboard Technology Satellite-3 of (STSAT-3) in 2013 November. The main mission is Paschen-α emission line survey along Galactic plane cosmic background (CIB) observation, particularly around north ecliptic pole region. For these missions, a wide field view (3.67 × 3.67°) with an angular resolution 51.6'' wavelength coverage...
By using the Optical Wide-field Patrol (OWL) network developed by Korea Astronomy and Space Science Institute (KASI) we generated right ascension declination angle data from optical observation of Low Earth Orbit (LEO) satellites. We performed an analysis to verify optimum number observations needed per arc for successful estimation orbit. The currently functioning OWL observatories are located in Daejeon (South Korea), Songino (Mongolia), Oukaïmeden (Morocco). Observatory is as a test bed....
Abstract We developed Korea Astronomy and Space science Institute (KASI) Near Infrared Camera System (KASINICS) to be installed on the 1.8 m telescope of Bohyunsan Optical Observatory (BOAO) in Korea. use a 512$\times$512 InSb array (Aladdin III Quadrant, Raytheon Co.) enable $L$ band observations as well $J, H$, $K_s$ bands. The field-of-view is 3${\rlap{\hskip.75pt{^\prime}}\hskip.75pt.\hskip1pt}$3$\times$3${\rlap{\hskip.75pt{^\prime}}\hskip.75pt.\hskip1pt}$3 with resolution...
One possible channel for the formation of dwarf galaxies involves birth in tidal tails interacting galaxies. We report detection a bright UV tail and several young galaxy (TDG) candidates post-merger NGC 4922 Coma cluster. Based on two-component population model (combining old stellar populations), we find that light predominantly comes from stars (a few Myr old). The Galaxy Evolution Explorer ultraviolet data played critical role parameter (age mass) estimation. Our mass estimates TDG are...
Die schwierige Aufgabe, einen Bromsubstituenten stereoselektiv an einem sp3-Zentrum einzuführen, wurde mithilfe einer das Nucleophil unterstützenden Abgangsgruppe gelöst (siehe Schema). Ein weiteres Merkmal der hoch stereo-, regio- und chemoselektiven Synthese von (+)-Microcladallen B ist Aufbau des α,α′-anti-Substrats für die Ringschlussmetathese durch eine Dianion-Alkylierung. TBDPS=tert-Butyldiphenylsilyl.
국내 육성 배 신품종과 신고 품종의 부위별 생리활성을 확인하고자 총 폴리페놀 화합물 및 플라보노이드 함량과 전자공여능, 아질산염 소거능 등 항산화 활성을 비교하였다. 함량은 품종별로는 추황배와 한아름이 다른 품종에 비해 높았으며, 과피, 과육, 과심이 각각 178~235, 95~113, 177~229 mg/100 g으로, 과피>과심>과육의 순으로 높아 부위별로 차이가 있었다. 품종별로 감천배가 29.2~40.2, 24.3~34.3, 26.9~38.8 g으로 과피가 과육과 과심에 높았다. 전자공여능은 감천배가, 부위별로는 과육(7.6~17.7%)이나 과심(29.1~38.2%)보다 과피(29.7~57.7%)에서 더 높은 소거능을 보였다. 아질산소거능은 18.0, 17.9%로 가장 과피(21.0~49.8%)>과심(11.8~16.2%)>과육(7.8~9.7%)의 특히 과피의 항산화활성이 우수하였다. This study was performed to confirm...
Inactive space objects are usually rotating and tumbling as a result of internal or external forces. KOREASAT 1 has been inactive since 2005, its drift trajectory monitored with the optical wide-field patrol network (OWL-Net). However, quantitative analysis in regard to attitude evolution never performed. Here, two tracking systems were used acquire raw measurements analyze rotation period satellites. During campaign 2013, was observed by 0.6 m class telescope operated Korea Astronomy Space...
The objectives of this study are to analyze the satellite visibility at randomly established ground sites, determine five optimal sites perform optical surveillance and tracking domestic satellites, verify acquisition observation time sufficient maintain precise ephemeris that have been already determined. In order accomplish these objectives, we analyzed for sun-synchronous orbit low earth middle satellites as well continuous along with fictitious track, calculate effective visibility. For...
Korea Astronomy & Space Science Institute (KASI) has installed a 1-m robotic telescope at Mt. Lemmon, AZ, in collaboration with company, Astronomical Consultants Equipment, Inc (ACE). The system is totally designed to make fully observations, and can be operated both interactive unattended modes. newly manufactured regarding mechanical optical parts. collect 80% of the incident light within ${0\rlap {.}{}^{\mathrm {\prime \prime }}5}$ an $f/7.5$ Ritchey-Chretien design. mount equatorial...
An optical tracking system has advantages for observing geostationary earth orbit (GEO) satellites relatively over other types of observation system. Regular surveying unidentified space objects with the can be an early warning tool safety five Korean active GEO satellites. Two strategies positioning on observed image Communication, Ocean and Meteorological Satellite 1 are tested compared. Photometric method a half root mean square error against streak method. Also eccentricity initial...
We estimated the orbit of Communication, Ocean and Meteorological Satellite (COMS), a Geostationary Earth Orbit (GEO) satellite, through data from actual optical observations using telescopes at Sobaeksan Optical Astronomy Observatory (SOAO) Korea Space Science Institute (KASI), Wide field Patrol (OWL) KASI, Chungbuk National University (CNUO) August 1, 2014, to January 13, 2015. The astrometric satellite were extracted World Coordinate System (WCS) in obtained images, geometrically...
In this study, both the altitude error due to refraction and range delay in ionosphere with respect frequency are extracted according radar elevation analyze effect of atmosphere on space surveillance radar. To achieve this, radio refractivity profile is modeled using measured data from domestic weather stations. Then, altitude-error ray tracing method, frequency. Further, considerations for design characteristics discussed based abroad proposed This analysis expected be utilized...
Radar sensors are used for space situational awareness (SSA) to determine collision risk and detect re-entry of objects. The capability SSA radar system includes sensitivity such as the detectable cross-section a function range tracking indicate time measurement errors. duration target staying in cell is short; therefore, signal-to-noise ratio cannot be improved through pulse integration method pulse-Doppler signal processing. In this study, improving during migration presented. detection...
An algorithm to automatically extract coordinate and time information from optical observation data of geostationary orbit satellites (GEO satellites) or geosynchronous (GOS is developed. The wide-field patrol system capable automatic using a pre-arranged schedule. Therefore, if this type analysis available, daily unmanned monitoring GEO can be possible. For acquisition for development, the COMS1 satellite was observed with 1-s exposure 1-m interval. images were grouped processed in terms...