• Journal of Astronomy and Space Sciences
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• v.15 no.2
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• pp.277-289
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• 1998

We report V-(B - V) CCD Color Magnitude Diagrams (CMDs) for 23 southern Galactic globular clusters. Limiting magnitudes for each cluster are between 18 and 20 magnitudes in V. Most CMDs show subgiant starts, red giant stars, and horizontal branch stars. From the CMDs, we have determined the horizontal branch magnitudes, V(HB), reddenings, E(B - V), and distances of each cluster.

• Journal of Astronomy and Space Sciences
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• v.11 no.2
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• pp.147-153
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• 1994

We present a deep(B, V) color-magnitude diagram (CMD) of the Galactic globular cluster NGC 4372. According to the recent inside-out picture of Galaxy formation, this cluster is predicted to be one of the oldest globulat clusters in the Galaxy. Our CMD shows a well defined main-sequence extending ∼ 2 magnitudes below the trunoff. Despite the uncertainty that stems from the small sample size of bright stars, comparison with the Revised Yale Isochrones suggests that this cluster may indeed be one of the oldest (∼16.6 Gyrs) globular clusters in our Galaxy.

• The Bulletin of The Korean Astronomical Society
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• v.32 no.1
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• pp.89.2-89.2
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• 2007

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.84.2-84.2
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• 2014

We report the discovery of a new Milky Way globular cluster (GC) candidate in the Galactic plane. We found this object during our WISE survey of star clusters in the Milky Way. We derived physical parameters of this object using the 2MASS JHK photometry. The color-magnitude diagram of the resolved stars shows a well-developed red giant branch (RGB). We derived its reddening, distance and metallicity. These results indicate that it is probably an old globular cluster, located behind the Galactic disk.

• Publications of The Korean Astronomical Society
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• v.25 no.3
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• pp.91-99
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• 2010

An increasing number of observations have confirmed the presence of multiple stellar populations in Galactic globular clusters. Multiple populations evidence come from the complex chemical pattern of stars hosted in GCs and from the split or broadening of different evolutionary sequences in the color-magnitude diagrams. Multiple stellar populations have been identified in Galactic and Magellanic Cloud clusters, as well as in external galaxies. In this paper I will summarize the observational facts.

• Journal of The Korean Astronomical Society
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• v.18 no.2
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• pp.70-78
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• 1985

From the kinematically unbiased sample of halo stars, the local mass density of halo dwarfs is estimated as $6.0{\sim}6.3{\times}10^{-4}m_{\odot}/pc^3$ by adopting a color-magnitude relation and a mass-luminosity relation. The derived halo mass density is not much different from the results of previous studies, which were derived from the kinematically biased sample of halo stars. Therefore it is confirmed that the local mass density of halo stars is far less than that required by Ostriker-Peebles to stabilize the galactic disk against barlike instabilities.

• Journal of The Korean Astronomical Society
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• v.31 no.2
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• pp.127-140
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• 1998

With a large format near-infrared camera at the 2.2-m telescope on Mauna Kea Observatory, we performed J K near-infrared observations for the metal rich globular cluster NGC6712. This cluster lies near the galactic plane and therefore suffers heavy reddening. We present the near-infrared color-magnitude diagram and also derive the metallicity ([Fe/H] ${\~}-0.96{\pm}0.27$) as well as its distance modulus ((m - M) ${\~}13.42{\pm}0.12$).

• Journal of The Korean Astronomical Society
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• v.29 no.2
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• pp.171-179
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• 1996

We have obtained the J K images of the central region of the globular cluster M3 (NGC5272), using the $256\pm256$ InSb array. We present JK photometry of bright red giant branch stars in the central $2'.2\pm2'.2$ region of M3. The infrared color-magnitude diagrams are presented. The comparison of the red giant branch of M3 with that of M13 confirms that both globular clusters have similar metal abundances.

• Journal of The Korean Astronomical Society
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• v.47 no.4
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• pp.137-145
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• 2014

The astrophysical parameters of four unstudied open star cluster candidates; Ivanov 2, 7, 9, and Harvard 9; are estimated for the first time using the PPMXL database. The stellar density distributions and color-magnitude diagrams for each cluster are used to determine the geometrical structure (cluster center, limited radius, core and tidal radii, the distances from the Sun, from the Galactic center and from the Galactic plane). Also, the main photometric parameters (age, distance modulus, color excesses, membership, total mass, relaxation time, luminosity and mass functions) are estimated.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.05a
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• pp.186-189
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• 2001

본 연구에서는 2종류의 색온도(4000 K, 2700 K)조건 하에서 작업자의 피로도를 평가하기 위하여 피험자에게 검색작업을 부가하고 주관평가 및 생리신호를 측정하였다. 주관평가는 ME(Magnitude Estimation)법의 설문지를 사용했으며, 생리신호는 ECG, 맥파, 피부전도도, 피부온도, 호흡, 뇌파를 측정하여 그중 ECG신호를 분석하였다. ECG신호 파라미터로서 IBI, BPM, 평균 BPM, LF/HF, CSI, CVI, CV-RR를 분석한 결과, 특히 CSI, CVI, CV-RR가 피로도와 상관관계가 높았다.