• Bulletin of the Korean Space Science Society
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• 1993.04a
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• pp.8-8
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• 1993

Long period eclipsing binary 32 Cygni was photometrically observed in 1992 at Yonsei University Observatory. Instrumental differential magnitude and standardized magnitude of this star show some intrinsic light variations. Some possible explanations will be discussed. BVRI photometric observations show that 30 Cyg may be a variable star. A further monitoring of 30 Cyg is therefore called for justification of such evidences.

• Journal of the Chungcheong Mathematical Society
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• v.25 no.4
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• pp.677-686
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• 2012

In this paper, we investigate the surfaces of revolution with light-like axis satisfying some equation in terms of a position vector field and the Laplacian with respect to the non-degenerate third fundamental form in Minkowski 3-space. As a result, we give some special example of the surfaces of revolution with light-like axis.

• Journal of Astronomy and Space Sciences
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• v.8 no.1
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• pp.53-61
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• 1991

UV light curve of 31 Cygni has been made from the IUE high dispersion specta. The depth of primary minimum of the light curve is 5.2 magnitudes because the B4 star's steep spectral gradient. The light curve has been analyzed by the method of Wilson and Devinney Differential Correction (WD). The radial velocities have been measured using the Mg II h lines. The spectroscopic elements have been determined by the method of WD. The change of the Mg II resonance doublet has been investigated based on the eight representative spectra taken at well distributed orbital phases.

• Journal of Astronomy and Space Sciences
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• v.9 no.2
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• pp.154-164
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• 1992

The Mg II lines been extracted from the IUE archival spectra of 32 Cygni to investigate the effect of the atmospheric eclipse. The UV light curve has been reduced from the continuum flux at the center wavelength of 2807.5 ${\AA}$ in the IUE spectra. The equivalent width of the Mg II k absoption line has been measured for each spectra. The results of the light variation and flux tracing of the absorption line at the vicinity of the primary eclipse confirmed the atmospheric eclipse. The atmospheric effect lasted until the phase 0.06 in the absorptin line tracing, while it lasted until the phase 0.02 in the UV light curve, respectively.

• KIEAE Journal
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• v.17 no.2
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• pp.21-28
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• 2017

Purpose: The early churches such as tabernacle, temple and synagogue had played a important role to form space concepts of western churches. Tabernacle and temple were designed with vertical axis which consisted of sanctuary, sanctum, outdoor yard. Synagogue was designed pew of congregation around pulpit to give a sermon. The aim of this paper is to analyze spatial principles of churches designed with vertical axis and centralized plan. Method: The concept of vertical axis plan succeeded to Basilica, Romanesque and Gothic churches, and the concept of centralized plan succeeded to Byzantine and Renaissance churches. Therefore, this paper analyzed spatial characteristics and role of light in churches according to epoch, and was progressed by examining the existing researches and case studies. Result: The churches designed with vertical axis plan realized spatial composition to show the concept of domus dei, and worship space was illuminated with mysterious light. The churches designed with centralized plan realized spatial composition to show the concept of domus ecclesiae, and light created dramatic holiness in worship space.

• Korean Institute of Interior Design Journal
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• v.14 no.3 s.50
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• pp.199-207
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• 2005

We recognize analysing and quantifying an effect of light and colors on people' psychological response changing according to environmental conditions as important. Therefore, this study intends to improve efficiency in realizing emotional design that contributes to creation of helpful and pleasant interior using architecture that is able to refresh human emotion or light and colors which are important factors in interior design. For the purpose, this study analyses an effect of colors in interior space and the effect of interaction between light and color through modeling to identify types of psychological response. And it is to present a generalized conclusion through an analysis of meaning of the two effects. The ultimate goal of this study is to identify the value and possibility of actual design. This study measures response on questionnaire through representative vocabulary by abstracting based on evaluation image selected through the 1st and 2nd preparatory research and grouping similar words. In next step, images represented both by light and colors are presented as virtual space and for data input and analysis based on psychological response corresponding to each image, this study uses SPSS 11.0 statistical package program to analyse data collected. The space to be experimented is a livingroom, a center of residential area.

• KIEAE Journal
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• v.9 no.1
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• pp.23-30
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• 2009

A lightcourt design is typically used to address issues concerning aesthetics, feeling, and mood. From the view point of environmental aspect, as an ecological shaft space, it plays a key role in controlling inner quality. In particularly, the lightcourt concept allows the exploitation of daylighting by bring natural light into the center of the building, thus eliminating dark deep spaces. Additionally, the lightcourt shades the inner space in summer. The amount of light available at the base of the lightcourt depends on a number of factors; translucency of the top, reflectance and the geometry of the space. In this paper is to exemplify a lightcourt configuration with a sloped wall. It promises the maximized a sense of freedom and daylighting availability. It is a matter of course that the lightcourt with open-top plays a role as a light source for the adjacent space to the lightcourt. A series of lighting simulation provides performance data of daylighting with changing photometric factors. For the case that a skylight is not available, an electric lighting design with metal halide lamps has been established to create luminous ceiling. As expected, a sloped lightcourt with open-top exposes its superiority of daylighting source. Ancillary considerations to enhance of daylighting potential for the adjacent space have been issued with performance data.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.142.1-142.1
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• 2012

During the photometric runs of the eclipsing binary V432 Per in 2006, we serendipitously discovered peculiar light variations of GSC 2855-0585 that imaged on the same target field. Its brightness decreased about 0.02 mag for about 0.15 days in all B, V, and R bands. The depth, duration, and box-shaped light curves are very similar to those of typical transiting exoplanets. We gathered the time-series data of GSC 2855-0585 from the SuperWASP public archive and detected the same light variations with a period of about 2.406 days. The period and transitlike features were confirmed by photometric follow-up observations at a predicted epoch in 2010 November. In order to estimate the mass of the companion that produced the light variations, we obtained 10 high-resolution spectra with different orbital phases in 2010 November and 2011 October-December. The radial velocities showed large variations of about 44 km/s. It indicates that the transitlike light variations do not originate from a transiting exoplanet, but from the single-lined spectroscopic eclipsing binary with a cool dwarf companion. Using the photometric and spectroscopic data, we estimated the physical parameters of the eclipsing binary GSC 2855-0585, such as orbital period, effective temperature, surface gravity, and mass.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.63-65
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• 2017

The zodiacal light emission is the thermal emission from the interplanetary dust and the dominant diffuse radiation in the mid- to far-infrared wavelength region. Even in the far-infrared, the contribution of the zodiacal emission is not negligible at the region near the ecliptic plane. The AKARI far-infrared all-sky survey covered 97% of the whole sky in four photometric bands with band central wavelengths of 65, 90, 140, and $160{\mu}m$. AKARI detected the small-scale structure of the zodiacal dust cloud, such as the asteroidal dust bands and the circumsolar ring, in far-infrared wavelength region. Although the most part of the zodiacal light structure in the AKARI far-infrared all-sky image can be well reproduced with the DIRBE zodiacal light model, there are discrepancies in the small-scale structures. In particular, the intensity and the ecliptic latitude of the peak position of the asteroidal dust bands cannot be reproduced precisely with the DIRBE models. The AKARI observational data during more than one year has advantages over the 10-month DIRBE data in modeling the full-sky zodiacal dust cloud. The resulting small-scale zodiacal light structure template has been used to subtract the zodiacal light from the AKARI all-sky maps.

• Journal of The Korean Astronomical Society
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• v.50 no.3
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• pp.41-49
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• 2017

We conduct BVRI and R band photometric observations of asteroid (5247) Krylov from January 2016 to April 2016 for 51 nights using the Korea Microlensing Telescope Network (KMTNet). The color indices of (5247) Krylov at the light curve maxima are determined as $B-V=0.841{\pm}0.035$, $V-R=0.418{\pm}0.031$, and $V-I=0.871{\pm}0.031$ where the phase angle is $14.1^{\circ}$. They are acquired after the standardization of BVRI instrumental measurements using the ensemble normalization technique. Based on the color indices, (5247) Krylov is classified as a S-type asteroid. Double periods, that is, a primary period $P_1=82.188{\pm}0.013h$ and a secondary period $P_2=67.13{\pm}0.20h$ are identified from period searches of its R band light curve. The light curve phases with $P_1$ and this indicate that it is a typical Non-Principal Axis (NPA) asteroid. We discuss the possible causes of its NPA rotation.