• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.64.2-64.2
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• 2017

The Population III (Pop III) stars are thought to be massive. If massive Pop III stars form binary system and they experience mass transfer via the Roche lobe overflow, this may significantly change the properties of the system. For example, mass transfer in such system may shorten the period of the system, forming short period binary black hole (BBH) system, which is the most promising candidate for recently detected gravitational wave radiation sources. Also, there is an expectation that due to the stripped envelope of donor star by mass transfer, this system can play a significant role in the cosmic reionization by emitting more UV photons. However, this outcome highly depends on the initial properties of the system. We perform grid calculation on Pop III binary models with various initial primary masses (20 ~ 100 solar mass), initial separations, and initial mass ratios (q = 0.5 ~ 0.9). We find that 1) in most cases binary models show no increase in the number of ionizing photons and 2) formation of short period BBH system via mass transfer is highly unlikely.

• The Bulletin of The Korean Astronomical Society
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• v.34 no.2
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• pp.80.1-80.1
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• 2009

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.146.2-146.2
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• 2011

In this study, we have derived the abundances of several elements ? Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Co, Ni - for the six F G K type stars in IC 2391 and the seven stars in NGC 6475. The spectra of those stars are taken from UVES POP archive data, of which resolution is 80,000. To derive the abundances of those elements, TAME (Tools for Automatic Measurement of Equivalent-widths), Kurucz stellar atmospheric model, and MOOG code are used. The stellar parameters (effective temperature, log g, metallicity, microturbulent velocity) are determined from the iron lines. The results provide the abundance differences of chemical elements between two open clusters, IC 2391 (a member of Gould Belt) and NGC 6475 (non-member of it), which would lead to better understanding about Gould Belt.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.83.2-83.2
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• 2010

To understand about Gould Belt, we intend to study chemical abundances for two young open clusters - IC 2391 which is a member of Gould Belt and NGC 6475 which is not. UVES POP (Ultraviolet and Visual Echelle Spectrograph Paranal Observatory Project) provides the spectra of twelve stars in IC 2391 and five stars in NGC 6475 with spectral resolution R of 80,000. In this study, we have determined the stellar parameters (Teff, logg, metallicity, and microturbulant velocity) using Fe I and Fe II lines. The equivalent widths of iron lines have been measured by TAME. The results of stellar parameters are presented.

• Journal of the Korean Society of Costume
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• v.58 no.6
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• pp.69-84
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• 2008

Considering that star reflects the image of current society, analyzing fashion of celebrity is to read ideal type and demands of beauty of the era. Especially the rock music-represents youth culture that last on present day-born in 1960's, and it is considered to a significant decade in pop music history. Thus this research will analysis rock star's fashions in iconological view of E. Panofsky. The aim of this document is Clarifying how the fashion of pop stars appeared and what formed its worth. As a result of analyzing fashions of rock star in 1960's, it is available to find these sameness and difference. The Mods borrowed images of the past, and introduce the elite modernism and shows very urban style. The Folky and the Psychedelic showed post-structuralism propensity against industrial society, in the case of the Folky it induced styles that symbolize labor class to realize social worth. And as an aftereffect of war and repulsion of commercial worth, they embody nature-returning peasant look so that it shows pastoral mood in total. The Psychedelic express somewhat struggling escapism and it generated illusionary images with quests to superego and glorification to psychedelic status. The Folky and the Psychedelic are same in the side of introducing existentialism, this occurred by using ethnic factor. But the Folky showed plain outlook by pop propensity, on the other hand, the Psychedelic showed magnificent outlook such as optical art, pop art, and futurism ought to express merrymaking culture. And common feature of these is introduction of unisex mod which is came after the change of gender role. Thus each star or group has professed special ideology into their culture and it is reflected to acts which is including music and dress style. This affair is analyzed like these two things. The mass of people schemes their identity with inducing special ideology to their culture at the first. And the purpose to archive cultural hegemony in inter-social class at the next.

• Cartoon and Animation Studies
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• s.41
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• pp.379-405
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• 2015

The purpose of this thesis is to seek the methodologies for forming the fandoms of the Theatre. For the research, I explain by giving the example of the K-POP, of which the fandom has already been spread. Afterwards, I describe about the items which can substitute the plays and about the limits. By escaping from the passive consumptions, the fandoms have been expanded to the domain in which the culture is reborn. The cultural activities of the fandoms have come out of simply liking the fans, and the domain has been widened to the social activities. In the case of the K-POP, it has gone beyond Korea and has the fandoms in the whole world. Regarding the reasons why the fandoms could be formed in relation to the K-POP, firstly, it is because the project-type stars made by the large-scale agency had existed. Secondly, it is because the methods of accessing the contents had become simple through the online proliferation, such as the YouTube and the SNS's. Lastly, it is because the cultural activities of the fandoms give the joys, thereby continually maintaining the fandoms. If this is substituted for the Theatre, in the case of the Theatre, in order for the large-scale agencies to make the plans for and train the actors and the actresses, there are, somewhat, the excesses. However, if a PR method suitable for the online environment is developed and if the common joy is given to the audience of the Theatre, there is the possibility that the fandoms can be invigorated regarding the Theatre. Although, with regard to the K-POP and the Theatre, there exist the differences between the contents, if the methodologies of the K-POP fandoms, which have invigorated the fandoms and have been managing stably, are substituted for the plays, the invigoration of the fandoms is possible regarding the Theatre, too.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.42-42
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• 2012

The First stars (Pop.III stars) in the universe are expected to be formed between the recombination era at z - 1100 and the most distant quasar (z - 8). They have never been directly detected due to its faintness so far, but can be observed as a background radiation at around 1${\mu}m$ which is called the Cosmic Near-Infrared Background (CNB). Main part of the CNB is thought to be redshifted Lyman-alpha from gas clouds surrounding the Pop.III stars. Until now, the COBE (COsmic Background Explorer) and the IRTS (Infrared Telescope in Space) observed excess emission over the background due to galaxies. To confirm the COBE and the IRTS results and pursue more observational evidences, we carried out the sounding rocket experiment named the Cosmic Infrared Background ExpeRiment (CIBER). The CIBER is successfully launched on July 10, 2010 at White Sands Missile Range, New Mexico, USA. It consists of three kinds of instruments. We report the results obtained by LRS (Low Resolution Spectrometer) which is developed to fill the uncovered spectrum around 1${\mu}m$. LRS is a refractive telescope of 5.5 cm aperture with spectral resolution of 20 - 30 and wavelength coverage of 0.7 to 2.0${\mu}m$. After subtracting foreground components (zodiacal light, integrated star light and diffuse galactic light) from the sky brightness of observed five fields, there remained significant residual emission (even for the lower limit case) consistent with the IRTS and the COBE results. In addition, there exists a clear gap at 0.7 - 0.8${\mu}m$ in the CNB spectrum over the background due to galaxies according to recent results (Matsuoka et al. 2011; Mattila et al. 2011). The origin of the excess emission could be ascribed to the Pop.III stars with its active era of z = 7 - 10.

• Journal of Korea Multimedia Society
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• v.23 no.1
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• pp.74-84
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• 2020

In November 2018, virtual pop band K/DA, with the use of holograms and actual K-pop girl group members, performed its debut album titled "POP/STARS" at the opening ceremony of the League of Legends S8 final, hosted by Riot Games. The fan culture that exists for real singers adapts itself to virtual bands, and K/DA, consisting of virtual characters, encouraging the production of user created content (UCC). However, this form of UCC is different from the most common one, meaning that this type of band generates another way of consuming content. Therefore, this study examines how K/DA's digital characters are transformed and reproduced by UCC and how the original producers' content differs from them. Firstly, the development of this study considers the open characteristics of UCC, such as user type, created motivation, created process, content type and sharing method. In the second part, the virtual idol Hatsune Miku and virtual band Pentakill will be analysed to understand UCC. Thirdly, K/DA will be analyzed as a case study based on three factors: created motivation, content type and sharing method. In this manner, this study aims to explain how UCC for virtual bands reproduce and consume original content and expand their commercial value.

• The Journal of the Korea Contents Association
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• v.12 no.1
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• pp.125-137
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• 2012

In this paper we draw from recent theoretical discussions of fan culture and the new media technologies to explore how online communities contribute to new forms of K-pop fandom. We suggest that these online sites play an important role in setting the new stage of dissemination and dialogue of K-pop knowledge, through which particular forms and spaces of online fan culture are being created and sustained. Moreover, these web-based communities challenge the existing concepts that have embraced interrelations between culture, consumption and technology. Based on an empirical study of YouTube, carried out using netnographic methods, this study tackles the following questions: how fans construct themselves as Korean pop fans through the online activities; how they exchange information and opinions of Korean stars; and, what meaning they extract from online file-sharing activities.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.59.1-59.1
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• 2017

Massive Population III black hole binary systems are one of the suggested candidate sources of the recently detected gravitational wave radiation (GWR). GWR detection from a black hole binary system requires a sufficiently short orbital separation at the time of their formation, such that they would undergo coalescence within the Hubble time. This condition cannot be simply fulfilled by a short initial period, because binary interactions such as mass transfer and common envelope evolution can largely change the orbital parameters and the masses of stellar components. Here, we discuss the possibility of black hole binary mergers from massive Pop III binary systems, using a new grid of Pop III binary evolutionary models with various initial primary masses ($20M_{\odot}{\leq}M{\leq}100M_{\odot}$) and initial separations, for different initial mass ratios (q = 0.5 - 0.9).