• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.36-36
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• 2013

Globular clusters (GCs) are among the oldest stellar objects in the universe and provide valuable constraints on many aspects of galaxy evolution. GC systems typically exhibit bimodal color distributions the phenomenon of which has been a major topic in the area of GC research. GC color bimodality established a paradigm where scenarios to explain its origin require two GC groups with different formation origins. The GC division, asserted mainly by photometric color bimodality so far, has been viewed as the presence of two distinct metallicity subgroups within individual galaxies. In this study, we make use of spectroscopy of GC systems associated with two giant galaxies, M31 (the Andromeda) and M87 (NGC 4486), to investigate the GC bimodality and the underlying metallicity distributions. Recent spectroscopy on the globular cluster (GC) system of M31 with unprecedented precision witnessed a clear bimodality in absorption-line index distributions of old GCs. Given that spectroscopy is a more detailed probe into stellar population than photometry; the discovery of index bimodality may point to the very existence of dual GC populations. However, here we show that the observed spectroscopic dichotomy of M31 GCs emerges due to the nonlinear nature of metallicity-to-index conversion and thus one does not necessarily have to invoke two separate GC subsystems. We present spectra of 130 old globular clusters (GCs) associated with the Virgo giant elliptical galaxy M87, obtained using the Multi-Object Spectrography (MOS) mode of Faint Object Camera and Spectrograph (FOCAS) on the Subaru telescope. M87 GCs with reliable metallicity measurements exhibit significant inflection along the color-metallicity relations, through which observed color bimodality is reproduced from a broad, unimodal metallicity distribution. Our findings lend further support to this new interpretation of the GC color bimodality, which could change much of the current thought on the formation of GC systems and their host galaxies.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.40.1-40.1
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• 2012

In the hierarchical universe, galaxy merger is predicted to be frequent, and thus it is an important element for understanding galaxy evolution. In particular, star formation is greatly enhanced during the merger. The aim of this study is to understand the position and rate change of star formation caused by equal-mass edge-on mergers. We use the GADGET2- N-body/SPH code, and fully consider gas cooling, star formation, and supernova feedback. We show the star formation rate (SFR), and the magnitude and color evolution of the merger remnants for 18 different configurations varying orbit elements and inclinations of host galaxies against orbit planes. Then we construct the mock images of the remnants and investigate on how equal-mass galaxy merger affects the SFR and color/magnitude evolution while considering dust reddening. We conclude that over 90% mass of SF in equal-mass merger is in the central region. SF in tidal feature involves a small fraction of new stars and thus is difficult to detect unless deep imaging is performed. Around 55 ${\pm}$ 5 percent of gas turns into stars until the final coalescence which typically corresponds to 0.8, 1.2, and 2.5 Gyr for direct, parabolic, and elliptical orbit, respectively. This result is roughly consistent with Cox et al. 2000. We plan to implement this result into semi-analytic model of galaxy formation. Caveats and future work on merging conditions are discussed.

• The Research Journal of the Costume Culture
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• v.14 no.6
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• pp.945-955
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• 2006

The purpose of this study was to examine the effect of hair style and hair color on women's impression formation. The experimental design was $2{\times}3{\times}3$ (hair wave$\times$hair length$\times$hair color) factorial design by 3 independent variables. Subjects were 343 women in Seoul. Four factors were derived to account for the dimensions of impression formation. These were neatness, sociability, attractiveness, and femininity. The straight hairs were evaluated neater than the permed hairs, and the permed hairs were evaluated higher in sociability and attractiveness. The short hairs were perceived highest in sociability, and the long hairs were perceived high in attractiveness and femininity. The black hairs were perceived highest in neatness, the bright brown were perceived high in sociability and attractiveness, and dark brown were perceived high in femininity. Attractiveness had significant interaction effects depending on three independent variables: hair wave, lengths, and colors. Long black straight hair was perceived most attractive, and midium length black straight hair was least attractive. The light brown permed hairs were perceived high in attractiveness regardless of hair length. In the case of straight hair, the longer the hair length was, the younger the object women were perceived. The women with the long permed hair were perceived older than the women with short and midium length permed hair.

• Journal of the Korean Geophysical Society
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• v.7 no.4
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• pp.255-267
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• 2004

Analysis of fracture system in a stone quarry mine is a critical importance in assessing the recoverable amounts of building stones as well as in establishing the systematic and efficient development plan. Rock formation comprising vein structure, degree of weathering, and compositon of minerals, is a critical factor of estimating the stone quality. The aim of this study is to provide desirable informations about both fracture pattern and rock formation by using Televiewer and Color-corescanner. Televiewer measurement were conducted at 7 boreholes in the gneiss quarry mine, Hadong, Kyeongsangnamdo province and the corresponding cores were scanned using Color-corescanner at the same place. In Televiewer images, all kinds of fractures were clearly observed and a better discrimination of stone quality can be identified. Meanwhile, the core images with high resolution (max. 20 pixels/mm) provided detailed informations on rock formation such as features of particles and fissures that can be nearly undetected by Televiewer.

• Korean Journal of Human Ecology
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• v.16 no.5
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• pp.1007-1019
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• 2007

The purpose of this study is to investigate the effect of achromatic shirt and chromatic tie combination on image of menswear. This experiment was designed by shirt color(N9, N7, N4, N2), tie color(red, orange, yellow, green, blue, purple), tie tone(vivid, light, dull, dark), and perceiver gender(a male, a female). The experimental materials developed for this study were a set of stimulus and response scales. The stimuli were 96 upper body photographs and 26 7-point bi-polar adjectives were used to evaluate the image. The subjects of this research were 480 male and 480 female college students. The data was analyzed by using SPSS program. Analysis methods were four-way ANOVA. The items of the adjectives were classified into 4 image factor: potency, activity, attractiveness, and visibility. Shirt color, tie color, tie tone influenced on the 4 image dimension greatly by interaction as well as independently. Dull or dark tone tie had an effect on the formation of potency image. And white color shirt, vivid or light tone tie had an effect on the formation of activity image. White or black shirt had a positive effect on attractiveness, and black shirt or vivid tone tie was effective for visible image.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.129-130
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• 2008

In this study, we implement the color image processing algorithm to analyze the quantitative assessment of denticulus by computing spectral characteristics in HGB color domain. We can observe that we can utilize the normalized HGB color feature to assess the quantitative formation of denticulus.

• Journal of the Korean Applied Science and Technology
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• v.19 no.3
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• pp.189-197
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• 2002

The color stability and purity from OLED is of current interest. Aggregation of dyes alters the device color after fabrication of the devices. Exciplex and electroplex formations have been proposed to explain the aggregate color change. We investigate the possibility of exciplex formation and propose the new electroplex state that can cause the bathochromic shift of the electroluminescence spectrum from the devices with TPD/PBD layers. The photoluminescence maximum of the device was 420nm, and the electroluminescence maximum of the device to became 480nm. The bathochromic shift cannot be attained with photoluminescence study with highly concentrated TPD/PBD mixture. This clearly indicates that the 480nm spectrum of the devices is not resulted from the exciplex formation with TPD and PBD. We observed the overshoot in EL spectrum from the OLEDs. The most intense overshoot was observed at 460nm, which may be due to the aggregates that are formed after the electric field has been removed from the devices.

• Corrosion Science and Technology
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• v.3 no.5
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• pp.187-193
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• 2004

We have investigated the differences between the general corrosion and microbiologically influenced corrosion (MIC) of steels in terms of electrochemical behavior and surface phenomena. Corrosion potential of steels in the absence of SRB (sulfate-reducing bacteria) shifted to a low level and was maintained throughout the experimental period (40 days). The potential in the presence of SRB, however, shifted to a noble level after 20 days' incubation, indicating the growth of SRB biofilms on the test metal specimens and a formation of corrosion products. In addition, the color of medium inoculated with SRB changed from gray to black. The color change appeared to be caused by the formation of pyrites (FeS) as a corrosion product while no significant color change was observed in the medium without SRB inoculation. Moreover, corrosion rates of various steels tested for MIC were higher than those in the absence of SRB. This is probably because SRB were associated with the increasing corrosion rates through increasing cathodic reactions which caused reduction of sulfate to sulfide as well as formation of an oxygen concentration cell. The pitting corrosions were also observed in the SRB-inoculated medium.

• Corrosion Science and Technology
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• v.17 no.6
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• pp.301-309
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• 2018

If galvanized steel is exposed to an outdoor environment, atmospheric corrosion will occur with time and red rust will form when the sacrificial protection capacity of zinc reaches its limit. With corrosion, the surface appearance of steel changes, and the properties of the exterior materials degrade. In this study, two kinds of galvanized steel, (GA and GI specimens) were subjected to an outdoor exposure test for 36 months in six regions of Korea. Chrominance (color, chroma, and brightness) and glossiness surface analyses were performed. The color change was not significant, regardless of the exposed area or the specimens tested. With increasing exposure times, the GA specimen became blackened by the formation of zinc oxide, and red coloration was increased by the formation of red rust. As the exposure time of GI specimen increased, the surface proceeded to blacken, but no red rust was formed and the color did not change significantly. Regardless of the outdoor exposure area or the specimen, longer exposure times led to lower glossiness, and this behavior appears to be influenced by the formation of zinc oxide.

• Journal of the Korean Society of Costume
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• v.20
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• pp.17-31
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• 1993

The purpose of this study is to inquire into the influence of appearance cues on the intellectual impression formations, whether there are differen-ces in the impression formation between the case which the appearance is partially percepted and the case wholely percepted. The study consists of the experiment of the factorial design with 5 independent variables of Face (intellectual and social), Hair Style (intellec-tual and social), Clothing Style (intellectual and social), Textile Pattern(single, color, dot, and stri-pe), and Presentation Level of stimuli (upper-half and full-length). The outcomes of study are as follows : 1) The intellectual impression formation was influenced by face, clothing style, and textile pat-tern, but clothing style and textile pattern were more influential than face. When the models with intellectual face wore in intellectual clothing style, they gave more additional intellectual impression. And when intellectual clothing was in single color, it conveyed more intellectual impression. Hair style had no main effect but it influenced on the impression formation through interaction with other variables. 2) There were differences in the formation of the intellectual impressions between the case the appearance was partially percepted and the case wholely percepted. The case of full-lenth pressen-tation was more influential than that of upper-half presentation.