• Journal of The Korean Astronomical Society
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• v.49 no.5
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• pp.199-208
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• 2016

We present photometric results of the δ Sct star V1162 Ori, which is extensively monitored for a total of 49 nights from mid-December 2014 to early-March 2015. The observations are made with three KMTNet (Korea Microlensing Telescope Network) 1.6 m telescopes installed in Chile, South Africa, and Australia. Multiple frequency analysis is applied to the data and resulted in clear detection of seven frequencies without an alias problem: five known frequencies and two new ones with small amplitudes of 1.2-1.7 mmag. The amplitudes of all but one frequency are significantly different from previous results, confirming the existence of long-term amplitude changes. We examine the variations in pulsation timings of V1162 Ori for about 30 years by using the times of maximum light obtained from our data and collected from the literatures. The O − C (Observed minus Calculated) timing diagram shows a combination of a downward parabolic variation with a period decreasing rate of (1/P)dP/dt = −4.22 × 10⁻⁶ year⁻¹ and a cyclic change with a period of about 2780 days. The most probable explanation for this cyclic variation is the light-travel-time effect caused by an unknown binary companion, which has a minimum mass of 0.69 M_⊙. V1162 Ori is the first δ Sct-type pulsating star of which the observed fast period decrease can be interpreted as an evolutionary effect of a pre-main sequence star, considering its membership of the Orion OB 1c association.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.53-58
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• 2020

Many stars are delivering various contents such as real time talks through Internet personal broadcasting to communicate with fans. For stars and entertainment companies that expect the effect of communicating with fans through Internet broadcasting, it can be said that it is important to grasp viewers' viewing motivation and satisfaction. Thus, we analyzed the viewing motivation and satisfaction of Chinese viewers' Internet personal broadcasting of famous celebrities based on the uses and gratifications approach. To this end, an online survey was conducted, and as a result, 'emotional motivation' and 'functional motivation' were found as Chinese viewers' motivation for viewing Internet personal broadcasting of famous celebrities. In addition, it was found that viewers' satisfaction increased as the viewers' 'emotional viewing motivation' increased. From the results of this study, it seems that a strategy of subdividing programs by reflecting the audience characteristics such as age and occupation is needed. It can be a way to expand the number of viewers and the intended broadcasting effect by designing and producing programs for personalized celebrity internet broadcasting by segmenting audiences.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.79-82
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• 2015

The physical and chemical properties of prestellar cores, especially massive ones, are still far from being well understood due to the lack of a large sample. The low dust temperature (< 14 K) of Planck cold clumps makes them promising candidates for prestellar objects or for sources at the very initial stages of protostellar collapse. We have been conducting a series of observations toward Planck cold clumps (PCCs) with ground-based radio telescopes. In general, when compared with other star forming samples (e.g. infrared dark clouds), PCCs are more quiescent, suggesting that most of them may be in the earliest phase of star formation. However, some PCCs are associated with protostars and molecular outflows, indicating that not all PCCs are in a prestellar phase. We have identified hundreds of starless dense clumps from a mapping survey with the Purple Mountain Observatory (PMO) 13.7-m telescope. Follow-up observations suggest that these dense clumps are ideal targets to search for prestellar objects.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.645-647
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• 2015

We have initiated a Very Long Baseline Interferometer (VLBI) monitoring project of 36 methanol maser sources at 6.7 GHz using the Japanese VLBI Network (JVN) and East-Asian VLBI Network (EAVN), starting in August 2010. The purpose of this project is to systematically reveal 3-dimensional (3-D) kine-matics of rotating disks around forming high-mass protostars. As an initial result, we present proper mo- tion detections for two methanol maser sources showing an elliptical spatial morphology, G 002.53+00.19 and G 006.79-00.25, which could be the best candidates associated with the disk. The detected proper motions indicate a simple rotation in G 002.53+00.19 and rotation with expansion in G 006.79-00.25, respectively, on the basis of disk model fits with rotating and expanding components. The expanding motions might be caused by the magnetic-centrifugal wind on the disk.

• Journal of Korea Entertainment Industry Association
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• v.15 no.6
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• pp.23-33
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• 2021

Under the long-term influence of COVID-19, offline activities were interrupted and online communication became the main way. With the rapid development of Korean Wave and network information technology, there have been many entertainment communication platforms. Fans can communicate with stars and other fans and share information through entertainment and communication platforms. This can improve users' perception of the value of entertainment communication platforms, arouse emotional resonance and have a positive impact on users' platform recommendation intention. In this study, the influence of user interaction, identity and recommendation intention of entertainment communication platforms was investigated by questionnaire. The results are as follows: First, the interaction between fans and content has a positive effect on psychological and behavioral identity. Second, the interaction between fans does not affect their psychological and behavioral identity. Third, the interaction between fans and stars has a positive impact on psychological identity and behavior identity. Fourth, psychological identity and behavioral identity have a positive impact on community members' willingness to recommend. Behavioral identity plays a partial mediating role between psychological identity and recommendation intention. Based on the above analysis results, the present situation, limitations and future research directions of this study are put forward.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.4
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• pp.538-548
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• 2000

A study analyzes the eclectic trend shown in Andy Warhol look to explain the pluralistic aspect which is expressed in the late 20th century's fashion. Eclecticism is a trial to dismantle the barriers between pure art and popular art, high culture and low culture. This pursues harmonious accommodation and coexistence of all areas without being confined in the conventional lofty taste or high art. This thesis studies the characteristic aspects of the eclectic trend by classifying this trend into sell culture, mass media and fashion around the Andy Warhol look. The sexual eclectic trend in Warhol look is bisexual one shown in clubland and the world of modeling and supplies fashion with abundant expression and ambiguity. Warhol established cultural eclecticism by compounding high cultural factors and low cultural factors. broke up the boundary between street fashion and high fashion and escaped from the fixed idea on materials and design. Also he generalized and democratized specialty or nobility conventional paintings had possessed through introducing repetition and mediocrity and fully utilized every kind of mass media, Hollywood movie stars and daily necessaries in producing works. Andy Warhol who asserted‘Business Art’that was the mixed form of artistry and commercialism had creative and futuristic taste and proposed the direction to develop current fashion and art where the concept of economy is importantly brought into relief.

• Journal of Digital Convergence
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• v.12 no.8
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• pp.303-308
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• 2014

In this paper, a ferrite sheet at the back of the smartphone by type, pattern, stars, the thickness of the recognition distance by attaching the NFC optimum ferrite sheet simulation was designed. Characterized by patterns rather than the Full-type I-type communication distance of about 1 ~ 2mm more extended. Ferrite sheet metal by applying the NFC antenna is effective in improving the characteristics were confirmed. In the case of the pattern C, the permeability is 140, a thickness of 0.1mm, Full-type ferrite sheet when applied to NFC communication distance than normal electromagnetic absorber is increased from 45 to 59 was confirmed that.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.46.4-47
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• 2015

Carnegie Hubble Program II (hereafter CHP II) is a large Hubble Space Telescope (HST) observing campaign in the cycle 22 composed of a total of 184 orbits (132 primes + 52 parallels), which aims to measure H0 directly with an unprecedented accuracy. Unlike our previous efforts in CHP I which used Cepheids as a yardstick, CHP II takes the Population II (Pop II) distance indicators such as RR Lyraes and tip of the red giant branch stars (TRGBs) to set up a new calibration to Type Ia supernovae (SN Ia) distance. The Pop II distance scales have two immediate advantages over the classical Cepheid method: 1) The period-luminosity relation of the RR Lyrae has a scatter that is a factor of 2 smaller; 2) The RR Lyrae/TRGB distance scale can be applied to both elliptical and spiral galaxies. This will provide a great systematic benefit by ultimately allowing us to double the number of SN Ia distances based on geometry. By taking advantage of this Pop II route, we expect to measure H0 value to 3 % of error which will be the highest accuracy H0 measurement to date using the "Distance Ladder" method. In this talk I will present a brief background/overview on the CHP II, observations/data acquisition status, and ongoing research progress/preliminary results.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.52.1-52.1
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• 2015

We have recently installed SQUEAN on the 82 inch telescope at the McDonald Observatory, USA. This instrument consists of an ANDOR CCD camera, a focal reducer, an electronic box, an auto guiding system and a new filter wheel which holds up to 20 filters. Currently the filter wheel is equipped with Johnson-Cousins BVRI filters, SDSS rizY and isiz filters, and 50nm medium band pass filters (M625(625nm), M675(675nm), M725(725nm), M775(775nm), M825(825nm), M875(875nm), M925s(925nm), M975(975nm), and M1025(1025nm)). Our medium band pass filter system is suitable with SED fitting. Filter transformation methods are essential for time-domain observations including transient objects, e.g., supernovae, variable stars, and solar system bodies. In this work, we develop a series of equations to convert the open clusters photometry data within these filter systems.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.82.2-82.2
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• 2015

In this talk, we introduce the Lee Sang Gak Telescope (LSGT), a 0.43m telescope that can be operated remotely. This telescope was installed at the Siding Spring Observatory in 2015 October, and since then, it has been operated through a robotic reservation system, remotely from Korea. This telescope is now being used for educational and research activities of SNU Astronomy program. By placing the telescope at a place with an excellent astro-climate in Australia, the observation class activity can include objects in the southern hemisphere to the magnitude limit of V=20 mag at an exposure time of a few minutes. For example, Cepheid stars in Magellanic clouds can be observed during a class activity for constructing the classical Cepheid light curves that has been a key distance measure technique. Research activities such as transient observation and monitoring observation of AGN are possible, and we are currently running a high cadence supernovae search program by monitoring nearby galaxies intensively (see a presentation by C. Choi). The installation of the telescope was made possible from a support from the Seoul.