• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.24-24
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• 2003

We present preliminary results about the quasi-simultaneous near-infrared light curves of the long-period eclipsing polar V1309 Ori in the J, H, K', and K bands with almost complete orbital phase coverage using the CFHT-IR camera. The optical light curve in the V and R bands, obtained by 1.8m Telescope at BOAO, will be also presented. The shape and the amplitude of the orbital light curve change significantly from optical to near-infrared wavelengths.

• Journal of Astronomy and Space Sciences
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• v.26 no.3
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• pp.279-286
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• 2009

To study properties of the variation of the infrared emission of OH/IR stars, we collect and analyze the infrared observational data in K band for nine OH/IR stars. We use the observational data obtained for about three decades including recent data from the two micron all sky survey (2MASS) and the deep near infrared survey of the southern sky (DENIS). We use Marquardt-Levenberg algorithm to determine the pulsation period and amplitude for each star and compare them with previous results of infrared and radio investigations.

• Journal of the Korean Ceramic Society
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• v.25 no.1
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• pp.27-34
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• 1988

In order to investigate the reason of changes in the physical properties of glasses near the region for which R(Ga/Na)=1, spectroscopic studies using FT-IR and Raman spectroscopy have been carried out on Na2O.2SiO2 glass with addition of Ga2O3 from 0 to 35 mole %, i.e., from R=0 to 1.61. The main purpose of this work is to investigate the coordination number of Ga3+ in glass with variation of glass composition and to determine the existence of tricluster in the Ga-rich region for which R>1.0 in Na2O-Ga2O3-SiO2 system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.9C
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• pp.546-554
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• 2011

Near targets in the infrared (IR) images have the steady feature for inner region and the transient feature for the boundary region. Based on these features, this paper proposes a new method to extract the fine target shape of near targets in the IR images. First, we detect the boundary region of the candidate targets using the local variance weighted information entropy (WIE) of the original images. And then, a coarse target region can be estimated based on the labeling of the boundary region. For the coarse target region, we use the opening filter with an adaptive structure element to extract the fine target shape. The decision of the adaptive structure element size is optimized for the width information of target boundary by calculating the average WIE in the enlarged windows. The experimental results show that a proposed method has better extraction performance than the previous threshold algorithms.

• The Bulletin of The Korean Astronomical Society
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• v.32 no.1
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• pp.107-107
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• 2007

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.332-333
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• 2004

• Journal of the Korean Chemical Society
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• v.34 no.6
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• pp.676-679
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• 1990

• The Bulletin of The Korean Astronomical Society
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• v.30 no.1
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• pp.55.1-55.1
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• 2005

• Current Industrial and Technological Trends in Aerospace
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• v.8 no.2
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• pp.65-75
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• 2010

In 2014, Japan is scheduled to launch GCOM(Global Change Observation Mission)-C for the global change observation mission, where SGLI(Second-generation Global Imager) is planned for optical multi-channel observation ofa radiation budget and a carbon cycle. Depending on the spectral channels, SGLI consists ofS GLI-VNR(Visible Near IR) and SGLI-IRS(IR Scanning). Their main design schemes are mostly based upon those ofthe previous instruments ever developed in Japan, which is intended to reduce the development risk for the advanced performance. Accordingly, for the better understanding ofSG LI, the paper reviews the history oft he Japanese optical payloads from two different views: VNR and IR. Through the review, a comparison among the Japanese optical instruments is made to distinguish the development trend toward SGLI ofGC OM-C.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.37.1-37.1
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• 2013

We present our study of analyzing the photometric properties of the globular cluster (GC) system which resides in the extended halo of the central bright Coma cluster galaxy NGC 4874. The core of the Coma cluster of galaxies (Abell 1656) was observed with both the HST Advanced Camera for Surveys (ACS) in the F475W (g475) and F814W (I814) and Wide Field Camera 3 IR Channel (WFC3/IR) in the F160W (H160) filters. The data analysis procedure and GC candidate selection criteria are briefly described. We investigate the interesting "tilt" features in color-magnitude diagrams for this GC system and their link to the nonlinear color-metallicity relation for GCs. The NGC 4874's GC system exhibits a bimodal distribution in the optical g475-I814 color and much more than half the GCs fall in the red side at g475-I814 ~ 1.1. This bimodality is weakened in the optical-IR I814-H160 color; the quantitative analysis on the features of both color distributions using the Gaussian Mixture Modeling code proves the bimodalities are different. Both colors, thus, cannot linearly reflect the bimodality of an underlying metallicity, supporting the suggestion that observed bimodalities in extragalactic GC colors are the metallicity-to-color projection effect.