• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.1
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• pp.7-12
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• 2019

Clouds in the atmosphere are important variables that affect the temperature change by reflecting the radiant energy of the earth surface as well as changing the amount of sunshine by reflecting the sun's radiation energy. Especially, the amount of sunshine on the surface is very important It is essential information. Therefore, eye-observations of the sky on the surface of the earth have been enhanced by satellite photographs or relatively narrowed observation equipments. Therefore, cloud automatic observing systems have been developed in order to replace the human observers, but depending on the seasons, the reliability of observations is not high enough to be applied in the field due to pollutants or fog in the atmosphere. Therefore, we have developed a cloud observation algorithm that is robust against smog and fog. It is based on the calculation of the degree of aerosol from the all-sky image, and is added to the developed cloud reader to develop season- and climate-insensitive algorithms to improve reliability. The result compared to existing cloud readers and the result of cloud cover is improved.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.3
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• pp.35-45
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• 2008

Realtime visibility measurement using camera is a new method which can collect some realtime visibility data similar to those of the human eyes, and can replace the existing methods using the expensive optical equipment. There have been a few attempts to measure visibility by extracting depth and three-dimensional structure under bad weather conditions. However, if there are many movements of objects in the image, these approaches seem to be inappropriate. In addition, the realtime visibility measurement will require a relatively simple and fast processing. Typically the contrast degrades exponentially in the bad weather. Therefore, in this paper we propose an easy and quick method that extract contrast from images using a moving area filter and measure visibility by mathematically modelling of the relationship between image contrast and visibility. The moving area filter is used for removing the area of the sky and moving objects that affect visibility measurement on images. The method proposed here can make possible not only realtime visibility measurement from images taken by CCD cameras, but also steady visibility measurement by using the moving area filter in case of much traffic on the road.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.74.3-74.3
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• 2015

We present 2D- photometric decompositions of ~1,200 nearby dwarf galaxies. Our representative sample is derived from 'A catalog of Visually classified galaxies in the Local Universe'(Ann, Seo and Ha APJS,,,2015) of which galaxy morphological types are determined by visual inspection of color images using the Sloan Digital Sky Survey data release 7. In this catalog, dwarf galaxies were divided into 5 subtypes : dS0, dE, dSph, dEbc, dEblue with distinction of the presence of nucleation in dE, dSph, and dS0. The dSph types are less brighter than other types, and galaxies with nuclei are slightly brighter than those with no nuclei in the same types. Sersic index n have a range 1~1.5, and $dE_{un}$ and $dSph_{un}$ galaxies have n less than 1, and $dSph_n$ galaxies have largest values. We performed two-dimensional decomposition of galaxies using GALFIT, and analyzed their structural components, and residual features which are seen in the residual image.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.59.3-59.3
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• 2015

National Youth Space Center will complete installation of the NYSC 1m Telescope in this year. Before completion of the telescope, we present the software design of JTCS, and the preliminary result of tracking performance by JTCS and mount of the telescope. JTCS currently uses commercial software of the Sky X, for the real-time coordinates of various objects, such as asteroids, comets, and even satellites. In order to guarantee flexibility in CCD detectors, the MaxIm DL software was adopted and JTCS provides auto-guiding and scheduled image-taking with MaxIm DL. We are now stabilizing the telescope mount and JTCS with long-exposure tests, and gathering the preliminary data of tracking performance.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.127-129
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• 2017

We have observed ~60 Weak-line T Tauri stars (WTTSs) toward the Chamaeleon star forming region using the AKARI Far-Infrared Surveyor (FIS) All-Sky maps. We could not detect any significant emission from each source even at the most sensitive WIDE-S band. Then, we have performed stacking analysis of these WTTSs using the WIDE-S band images to improve the sensitivity. However, we could not detect any significant emission in the resultant image with a noise level of $0.05MJy\;sr^{-1}$, or 3 mJy for a point source. The three-sigma upper limit of 9 mJy leads to the disk dust mass of $0.01M_{\oplus}$. This result suggests that the disks around Chamaeleon WTTSs are already evolved to debris disks.

• Journal of Astronomy and Space Sciences
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• v.12 no.2
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• pp.256-264
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• 1995

This report presents the development procedure and the results of a prototype star sensor which can be used as one of the attitude sensors of the KITSAT-3. The star sensor is a major attitude sensor that can determine the 3-axis attitude information, by comparing between star corrdinates in the star catalog and the measured corrdinates. The 2 dimensional CCD camera is used for measuring the star corrdinates and the DSP(Digital Signal Processor) technology is applied to the image and signal processing. Using the prototype star sensor with thermoelectri cooling technique, we have succesfully obtained the star images around 4th magnitude at Sobaeksan Astronomy Observatory minimizing night sky effect.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.10
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• pp.1204-1211
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• 2012

Measurement and analysis results of the extracted radiation-patterns from the field-experiments which were conducted to acquire the generic technology for calibration and validation of the satellite SAR system(Synthetic Aperture Radar) are presented in this study. Prototype of active transponder is adjustable within maximum 63.1 dBsm of RCS (Radar Cross Section) and includes the receiving-function with external receiver. To increase an accuracy of these field experiments, we repetitively measured satellite SAR systems of the same operating mode(i.e., COSMO-SkyMed No. 2 & 3, hh-pol., strip-map himage mode, 3 m resolution). Then, the reliability of experimental results was cross-checked through analysis of the RCS of active transponder on SAR image. The property of azimuth radiation patterns of satellite SAR system extracted from them has $0.352^{\circ}$ of HPBW(half-power beamwidth), $0.691^{\circ}$ of FNBW(first-null beamwidth), and 11.17 dB of PSLR(peak to side lobe ratio), respectively.

• Cartoon and Animation Studies
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• s.27
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• pp.1-30
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• 2012

Oshii Mamoru attempts to project the perception of reality about his own modern world as it is through animation. The precedent studies on Oshii Mamoru put their focus on the point that his works have a tendency to represent the devastation of reality as the image of 'a ruin.' In addition, they gave an impression that Oshii Mamoru's animation has gradually developed to expose the 'realistic taste[beauty]' from the design perspective. However, this study is going to put its focus on the point that Mamoru's works were created as an attempt at finding the subversive possibility of the suppressed modern world under the modern capitalism in the aspect of 'everyday life' of the modern world. First, for its analytical purpose, this study intends to do that by dividing the work into the three layers such as space, body and everyday life. In Chapter II, this study, in relation with the issue of 'space' representation, analyzed the space in into the modern, mechanical, compactly capitalized space and also the space just like a closed circuit having the nature of 'repetition.' In Chapter III, this analyzed that suggests the body moving freely between a human named 'Kildren' and the inhuman from the aspect of character's body, through which Mamoru represents the capitalized, reified body of the modern world. In addition, this analyzed the extreme anxiety facing the body into the reflection of the phenomena of 'anxiety' and 'placelessness' consequent on the labor flexibility of the modern world. In Chapter IV, this study, on the basis of the analysis of layers of space & body, analyzed that the 'everyday life' of the modern world was represented in the respects of 'memory' and 'habit', and in the aspects of Mise-en-Sc$\grave{e}$ne, design and direction. In Chapter V, this rooted out the fact that Mamoru suggested the attempt at 'appropriation' based on his perception of reality about such a modern world. Such a finding includes unearthing the fact that Oshii Mamoru's work is raising a question about how to desert and appropriate the modern space. In conclusion of Chapter VI, this drew the conclusion that Oshii Mamoru's work represented the layer of 'everyday life' while dealing with the post-modern themes shown by the existing modern SF genre, provided the 'window' through which people can perceive the 'modern world radically by recommending an attempt at 'appropriation', and blazed a trail in a new realm of creation for animations.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.3
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• pp.327-335
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• 2011

A study on the RCS of a self-manufactured active transponder, which has a manually adjustable RCS, for SAR(Synthetic Aperture Radar) external calibration and image analysis at X-band is presented in this paper. The RCS of the active transponder was comparably analyzed using the lab-test and the COSMO-SkyMed SAR system, and also precisely analyzed the difference between the adjusted and estimated RCSs. A maximum RCS of the designed and manufactured active transponder is 60 dBsm. The active transponders with 60 dBsm and the adjusted RCS of 40 dBsm were measured using the single target calibration technique(STCT) and 2D target scanning technique(2DTST). And the extracted RCS using power-spill integration technique in a SAR image was compared with the measured RCS of active transponder. The comparison results show that the measured and extracted RCSs are 59.7 dBsm, 40.2 dBsm and 57.3 dBsm, 39.2 dBsm, respectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.507-513
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• 2021

GPR (Ground Penetrating RADAR) is a sensor that inspects the pavement state of roads, sinkholes, and underground pipes. It is widely used in road management. MMS (Mobile Mapping System) creates a detailed and accurate road map of the road surface and its surroundings. If both types of data are built in the same area, it is efficient to construct both ground and underground spatial information at the same time. In addition, since it is possible to grasp the road and important facilities around the road, the location of underground pipelines, etc. without special technology, an intuitive understanding of the site is also possible, which is a useful tool in managing the road or facilities. However, overseas equipment to which this latest technology is applied is expensive and does not fit the domestic situation. LiDAR (Light Detection And Raging) and GNSS/INS (Global Navigation Satellite System / Inertial Navigation System) were synchronized in order to replace overseas developed equipment and to secure original technology to develop domestic equipment in the future, and GPR data was also synchronized to the same GNSS/INS. We developed software that performs georeferencing using the location and attitude information from GNSS/INS at the time of acquiring synchronized GPR data. The experiments were conducted on the road site by dividing the open sky and the non-open sky. The road and surrounding facilities on the ground could be easily checked through the 3D point cloud data acquired through LiDAR. Georeferenced GPR data could also be viewed with a 3D viewer along with point cloud data, and the location of underground facilities could be easily and quickly confirmed through GPR data.