• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.38.3-38.3
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• 2019

We present newly discovered dwarf galaxy candidates in deep wide-field images of NGC 1291 obtained with KMTNet. We identify 15 dwarf galaxy candidates by visual inspection within the virial radius of NGC 1291. Using imaging simulations, we demonstrate that our imaging data is complete up to 26 mag arcsec^-2 or -10 abs.mag with > 70% of the completeness rate. We also apply automated detection method to find the dwarfs. However, the completeness and the reliability are relatively low compared to the visual inspection. We find that structural and photometric properties of dwarf candidates such as effective radius, central surface brightness, Sérsic index, and absolute magnitude appear to be consistent with those of known dwarf galaxies in nearby groups and clusters, except for color. NGC 1291, residing in a relatively isolated environment, tends to accompany bluer dwarf galaxies (≃0.58) than those in denser environment. It shows that the quenching of dwarfs is susceptible to the environment.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.43.3-43.3
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• 2016

We present a library of high-resolution (R~45,000) and high signal-to-noise ratio ($S/N{\geq}200$) near-infrared spectra of 147 standard stars. High quality spectra were obtained with Immersion GRating INfrared Spectrograph (IGRINS) covering the full range of H ($1.496-1.795{\mu}m$) and K ($2.080-2.460{\mu}m$) bands. The targets are mainly selected as MK standard stars which have well-defined spectral types and luminosity classes, and cover a wide range of effective temperatures and surface gravities. The spectra were corrected for telluric absorption lines and absolute flux calibrated using Two Micron All Sky Survey (2MASS) photometry. We find new spectral indices in H and K bands and provide their EWs. We describe empirical relations between the measured EWs and stellar atmosphere parameters such as effective temperature and surface gravity.

• Journal of Dental Rehabilitation and Applied Science
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• v.20 no.2
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• pp.143-150
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• 2004

Endosseous implants have been used to provide anchorage control in orthodontic treatment without the need for special patient cooperation. However these implants have limitation like space requirement, cost, equipments. Recently titanium micro-implant for orthodontic anchorage was introduced. Micro-implants are small enough to place in any area of the alveolar bone, easy to implant and remove, and inexpensive. In addition, orthodontic force application can begin almost immediately after implantation. The mandibular first, maxillary first, mandibula second, and maxillary second molars were the four most commonly missing teeth in adult sample. In case of posterior molar teeth missing, deflective contacts in any position, over time, has produced pathologic change of occlusal scheme because of extrusion of opposing teeth. This case had interocclusal space deficiency by mandibular right molars missing over time. The micro-implants had been used for intrusion of maxillary right molars for interocclusal space. The micro-implant would be absolute anchorage for orthodontic movement. Therefore, the micro-implant would be effective method for correction of occlusal plane.

• Journal of Astronomy and Space Sciences
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• v.27 no.2
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• pp.69-74
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• 2010

We present new BVR CCD photometric light curves for the close binary star V445 Cep. A new photometric solution and absolute physical dimensions of the system were derived by applying the Wilson-Devinney program to our observed light curves and radial velocity curves published by Pych et al. The evolutional status of V445 Cep was found to coincide with those of the general low mass ratio contact binary systems.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.47.2-47.2
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• 2017

We present the results of astrometric observations using water masers around a semi-regular variable star R Crt. The observations were carried out for two years with the Korean VLBI Network (KVN). The absolute positions of the water masers from R Crt are successfully obtained at 10 epochs in total. By tracking the positions of the water maser emission, we directly measured the annual parallax and distance of R Crt. The measured distance to R Crt enables us to estimate the actual 3D velocity of water masers around R Crt. Our research suggests the possibility of performing astrometric studies with the KVN. As a next step, we are going to enhance the astrometric accuracy by observing SiO masers.

• The Transactions of the Korea Information Processing Society
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• v.6 no.10
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• pp.2630-2641
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• 1999

Most of the previous game development has proceeded in the approaches of the temporal-oriented synchronization because of producing game objects by using general authoring tools, and ad hoc or trial and error methods has been devised for representation of spatial concept. This paper is a study on the unification notation for spatio-temporal synchronization to conquest this fault. First of all, we classify game space as temporal object, spatial object, absolute/relative spatio-temporal space. The spatio-temporal relationships are divided into temporal extent, temporal location, spatial extent, and spatial location. In the paper the temporal and spatial relationships of game scene are defined to represent the synchronization, and we propose new unification notation by temporal and spatial concept to represent two concepts putting emphasis on space. Their relationships are presented on 3D by creating time axis related with time in scene unit of the two dimensional plane in the pivot on space. The usability of this representation method are shown by applying examples of game scenario.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.32.3-32.3
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• 2010

We have analyzed times of minima for six eclipsing binary systems which show asymmetric light curves. We found that five binary systems show period decrease and one system shows cyclic period variation. Three asymmetric light curves (SV Cen, RT Scl and VW Boo) are due to hot spot caused by mass transfer. Other three asymmetric light curves (AD Phe,, EZ Hya and TY Boo) are due to cool spot on the cooler component caused by magnetic activities. We also obtain absolute dimensions from photometric solution and spectroscopic solution by analyzing their light curves and radial velocity curves, collected from literatures, using 2007 version Wilson and Devinney computer code.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.32.4-32.4
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• 2010

Evolution of the Cosmos (ARCSEC). We have presented the evolutionary status of seven detached double line spectroscopic eclipsing binaries which are CD Tau, CM Lac, CW CMa, HS Hya, IT Cas, KM Hya, and ZZ Boo because the component stars in the binary systems still act as a single star. We determined the absolute dimensions of the binary systems using photometric and spectroscopic solutions by analyzing of the light curves and radial velocity curves. We chose evolutionary tracks of these binary systems. Using the luminosities, effective temperatures and masses. Finally we obtained ages and metallicity of the stars.

• Korean Institute of Interior Design Journal
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• v.17 no.3
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• pp.68-76
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• 2008

This study investigated composition elements and estimation of image in lobby from user viewpoint that is the central space of local cultural institution, and spectator mainly utilizes. Progress process of study develops investigation device including literature investigation, professional panel and lobby space image measurement tool through on-the-spot probe and, executed supporting research to spectator. As the result of the study, first, lobby space image exerts absolute effect to local cultural institution image-building, and is grasped on constituent that floor, ceiling, entrance and lighting and decoration is important in image-building of lobby space. Second, the image of the important lobby space was grasped in order of convenient image(M = 3.98) bright image(M = 3.87), and cozy image(M = 3.80). Third, the results on investigating semantic structure of the lobby image, emotional factor, styling factor, spatial factor, and peculiar factor are composed of important factors that decides image of lobby space. Fourth, as the result of image analysis for lobby space, the degree of satisfaction for the local cultural institution was entirely low against the importance. In particular, the image for convenience, individuality, locality and dignity was not sufficient in all the three places. Therefore, lobby design of local cultural institution shall also suggest more various lobby space image from culture oriented viewpoint.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.275-282
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• 2004

We completed the light curves of the contact binary CK Boo for 13 nights from June to July in 2004 using the 1-m reflector and BVR filters at Mt. Lemmon Optical Astronomy Observatory, and determined four new times of minimum light (three timings for primary eclipse, one for secondary). With contact mode of the 1998-version Wilson-Devinney binary model, we analyzed our BVR light curves and Rucinski & Lu (1999)'s radial-velocity ones. As a result, we found CK boo to be A-type over-contact binary ($f=84\%$) with the low mass ratio (q=0.11) and orbital inclination ($i=65^{\circ}$). Absolute dimensions of the system are determined from our new solution; $M_1=1.42Me{\odot},\;M_2=0.15M{\odot},\;R_1=1.47R{\odot},\;R_2=0.59M{\odot}$ and the distance to it is derived as about 129pc. Our distance is well consistent with that ($157{\pm}33pc$) from the Hipparcos trigonometric parallax within the limit of the error yielded by the latter.