• Journal of Astronomy and Space Sciences
• /
• v.17 no.2
• /
• pp.133-140
• /
• 2000

From the VI images of M13, obtained by using 2K CCD camera and the BOAO 1.8m telescope, we derive the(V - I) - V CMD of M13. From the shapes of red giant branch, the magnitude of horizontal branch, and the giant branch bump on the constructed CMD, we determined the metallicity of the globular cluster to be 1.74${\lesssim}$[Fe/H]${\lesssim}$-1.41. The good agreement between our determination of [Fe/H] and those determined by using other methods implies that the morphology of red giant and horizontal branches on (V - I) - V CMD's can be good indirect metallicity indicators of Galactic globular clusters.

• Journal of Astronomy and Space Sciences
• /
• v.13 no.2
• /
• pp.181-197
• /
• 1996

Thc CCD earth image experiment(CEIE) is one of the main payload of the KITSAT-1. Since it was launched on Age. 11, 1992, the CEIE has taken more than 500 images on the earth surface world-wide so far. An image from the space is very different from a feature on the real Earth surface due to various radiometric and geometric distortions. Preprocessing to remove those distortions has to take place before the image data are processed and analyzed further for various applications. This paper summarizes the result of the operation of the CEIE and describes the procedure to perform preprocessing including radiometric and geometric correction.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.250-253
• /
• 2007

Korean Multi-Purpose SATellite 5 (KOMPSAT-5) will be the first high resolution X-band SAR satellite of Korea. A critical parameter necessary for interpreting SAR images over the ocean is surface wind field. SAR is the only system that can provide a synoptic view of wind fields over the ocean covering large areas. However, there has been no X-band wind retrieval model. In this study, we evaluate the development of an X-band wind retrieval model and show the possibility of KOMPSAT-5 SAR on wind estimations using a combination of theoretical models.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.1B
• /
• pp.35-41
• /
• 2010

In this paper, we propose a 3D view design scheme which arranges 2D information in a 3D virtual space with a flexible interface and voice information. The scheme allows the user interface of the 2D image in 3D virtual space anytime from any view point. Voice information can be easily attached. It is this simple and efficient image and voice information arrangement in 3D virtual space that improves information transfer.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.2
• /
• pp.223.2-223.2
• /
• 2012

Grating spectrograph observation in near-infrared bands requires wavelength calibrations. We first need to extract order-strips from the echellogram data using flat images, and then to correct the spatial distortions and wavelength scales of the order strips using calibration arc lamps or the telluric OH emission lines. For very high resolution spectrograph using echelle, however, the arc lamps do not have enough emission lines in the order-strips, so we usually use the OH lines for accurate wavelength calibrations in wavelengths shorter than 2.3 microns. In this poster, we present wavelength calibration methods for longer wavelength bands using the telluric absorption lines in early-type stellar spectra and the telluric atmospheric transmission models. This technique will be applied to the data reduction pipeline for the IGRINS.

• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.1
• /
• pp.75.3-75.3
• /
• 2019

Understanding how ram pressure stripping (RPS) affects the star formation activity of cluster galaxies is one of the important issues in astrophysics. To examine whether we can identify any discernible trend in the star formation activity of galaxies undergoing ram pressure stripping, we study the star formation properties of galaxies in the Virgo cluster for which high-resolution HI images are available. We first classify galaxies in the Extended Virgo Cluster Catalog into different stages of RPS based on their HI morphology, HI deficiency, and location in phase space. We then examine various star formation activity indicators of these galaxies, which include starburstiness, g - r color, and WISE [3.4]-[12] color. No noticeable enhancement in star formation was identified for galaxies undergoing early or active stripping. Our results suggest that star formation activity at best seems to be enhanced locally in such galaxies, making it challenging to detect with integrated photometry. With the combination of HI deficiencies and locations in phase space, we were instead able to capture the overall quenching of star formation activity with increasing degree of ram pressure stripping, which agree with previous studies.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.2
• /
• pp.1064-1079
• /
• 2019

Information security has become increasingly important with the rapid development of mobile devices and internet. An efficient encryption system is a key to this end. In this paper, we propose an image encryption method based on the cross diffusion of two chaotic maps. We use two chaotic sequences, namely the Logistic map and the Chebyshev map, for key generation which has larger security key space than single one. Moreover, we use these two sequences for further image encryption diffusion which decreases the correlation of neighboring pixels significantly. We conduct extensive experiments on several well-known images like Lena, Baboon, Koala, etc. Experimental results show that our algorithm has the characteristics of large key space, fast, robust to statistic attack, etc.

• Journal of architectural history
• /
• v.32 no.4
• /
• pp.7-18
• /
• 2023

Recognizing that the debate on the original form of the Seokguram Grotto is closely related to the mythologization of the Seokguram Grotto, which is far from factual understanding, this paper is prepared to restore the Seokguram Grotto based on scientific facts. To this end, we will first analyze its active meaning and fiction from three directions: the founding legend, the rediscovery story, and the concept and discourse of the Line of sight for Buddha statue (對佛像視準線), which have contributed to the mythologization of the Seokguram Grotto. The original restoration of the Seokguram Grotto should be based on a scientific understanding of the Seokguram space. However, past debates and restoration attempts have been based on imagination and not on scientific knowledge. Therefore, Chapter 3 attempts a scientific analysis of the light environment of thr Seokguram Grotto and critically examines the existing errors and realistic mythological images to correct the public's spatial perception of Seokguram's architecture and to propose a rational restoration of Seokguram's architectural space.

• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.2
• /
• pp.77.1-77.1
• /
• 2019

We present the results of the merger fraction evolution for galaxies in NEP-Wide field depending on star formation mode and redshift. We select the galaxies which have AKARI 9 ㎛ detections as a sample for large number of galaxies. We use multi-wavelength data from GALEX to Herschel, and Subaru HSC i-band images for analysis. We classify the merger galaxies with using Gini and M20, which are non-parametric calculated by statmorph code. We obtain the total infrared luminosity from the SED modeling with using one band, AKARI 9 ㎛. We find that the merger fractions of galaxies in all different star formation mode increase as the redshift increases. However, with fixed mass range of 10.5 < log(M🞵) < 11.5, the merger fractions of starbursts significantly increase as the redshift increases compared to those of main sequence and quiescent galaxies. We discuss the implications of these results in this poster.

• Journal of the Korean Society of Costume
• /
• v.64 no.7
• /
• pp.128-142
• /
• 2014

In the new media age, the importance of personal style is highlighted, as the fashion recipients independently create their own images by transforming and recombining the fashion information gathered from the fashion blogs - the most representative form of social networks. The study aims to identify the types and styles of imaginary ego-images represented on the personal fashion blogs as a new space of self-expression, based on Lacan's gaze; the imaginary of the unconscious world and the ego-concept. According to literature search, the imaginary ego-image is classified as narcissism, regression, identification, and virtuality. In the case study, Narcissism is represented mostly as bloggers' satisfaction and beliefs about their fashion styles. The degeneration represents childhood images including a mother, as well as retro and vintage images that recreate the fashions of bygone eras - such as medieval, $19^{th}$ or 20th century fashion. Identification is the connection with the various areas of culture and art, especially movies and music. Virtuality represents hypothetical situations of mythical, fairy tale-like, surreal, or dreamlike atmospheres and hypothetical bodies that appear removed, disassembled, or crooked. The imaginary ego-images emerged on the personal fashion blogs are also classified into specific style depending on the attributes of the ego images-such as kidult style, retro style, ethnic style, and surreal style.