• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.70.2-70.2
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• 2014

We developed a three-dimensional (3D) magnetohydrodynamic (MHD) simulation code to reproduce the structure of a solar wind and the propagation of a coronal mass ejection (CME) through it. This code is constructed by a finite volume method based on a total variation diminishing (TVD) scheme using an unstructured grid system (Tanaka 1994). The grid system can avoid the singularity arising in the spherical coordinate system. In this study, we made an improvement of the code focused on the propagation of a CME through a solar wind, which extends a previous work done by Nakamizo et al. (2009). We first reconstructed a solar wind in a steady state from physical values obtained at 50 solar radii away from the Sun via an MHD tomography applied to interplanetary scintillation (IPS) data (Hayashi et al. 2003). We selected CR2057 and inserted a spheromak-type CME (Kataoka et al. 2009) into a reconstructed solar wind. As a result, we found that our simulation well captures the velocity, temperature and density profiles of an observed solar wind. Furthermore, we successfully reproduce the general characteristics of an interplanetary coronal mass ejection (ICME) obtained by the Helios 1/2 spacecraft (R. J. FORSYTH et al. 2006).

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.71.2-71.2
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• 2015

We present the high-resolution near-infrared spectra of standard stars observed with Immersion Grating Infrared Spectrograph (IGRINS). IGRINS covers the full spectral range of H and K bands simultaneously with a high spectral resolution (R=40,000), revealing many previously undetected and/or unknown lines. In this work, we present preliminary results of spectroscopic diagnostics for stellar physical parameters. Our ultimate goal is to provide a library of near-infrared spectra of standard stars, which covers all spectral types and luminosity classes, with a high-resolution and high signal to noise ratio ($SNR{\geq}200$).

• The Journal of Sustainable Design and Educational Environment Research
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• v.14 no.2
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• pp.1-11
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• 2015

The existing school facility recommendations enacted in 1997 has not been suitable for current school curriculum. The objective of the paper is to present the school building area reflecting the current education policies and curriculum. This paper firstly reviewed previous school facility recommendations through literature review. Secondly, the statistical approach was carried out for analyzing the present situation of school building area by using statistical database of Korean Educational Development Institute. The paper did the field investigation and questionnaire. And, the final step proposed the school building area standards(minimum, optimum, maximum) by space program using Nelson model. The contents of analyzing space organization are 'entry and placement, outdoor space', 'space program' and 'phase structure and organization of unit space'.

• Journal of Korean Society of Rural Planning
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• v.22 no.4
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• pp.37-47
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• 2016

The purpose of this study was to analyze the loss of open space of schools in Ulaanbaatar city and found out main causes of the conversion trend of open space to suggest alternatives. 76 designated sites were selected from 118 public schools within 6 districts of Ulaanbaatar city. These 76 schools were eligible for analysis of the open space change between 2005 and 2015 with Google Earth Pro. The results showed that $175,048m^2$ open space was developed and two dominant types of open space conversion were found; 1) constructions of school facilities such as soccer field, extended school buildings, parking lot, sidewalk, and square, and 2) constructions of apartment buildings and service facilities such as community center, pedestrian, sports facilities, and parking lot. Apartment complex development has commonly happened in all districts and caused bigger open space loss than other types of development. Chingeltei district is located in the center of Ulaanbaatar city, and schools in this district lost the biggest open space, $50,036m^2$/35.24% over 10 years. The rate of open space loss seemed to be related to the distance from the urban center and open space loss was an ongoing event in Ulaanbaatar city. This trend would not be improved without a strong regulation, so, in this study, making strict regulations that prevent conversions of open space were suggested to conserve open space in Ulaanbaatar city.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.229-233
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• 2006

The purpose of this study is to propose the standards for dimension system for unit space of the classroom in elementary school. The curriculum of elementary school has changed. It has been reflected the architectural plan of classroom of the nationwide elementary school. However the Ministry of Education repealed the statue about the facilities of the schools on September in 1997 and the new education curriculum -the 7th curriculum- demands various activities in the classroom. So we need to another size of unit space of the classroom in elementary school because the size of unit space will affect the quality of education. This study represents that the size of unit plan is based on the size of human body, education curriculum, established day, the number limit of classroom and teaching tools. In this study, regression analysis is used to find out a part of the body-size of Korean.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.79.1-79.1
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• 2019

The Schwarzchild-Chang telescope is a confocal off-axis two mirror telescope with D = 50 mm, F = 100 mm and FOV = 8 ° × 8 °. Unlike common off-axis telescopes, the mirrors of the Schwarzchild-Chang telescope share their focal points to remove the linear astigmatism. In this poster, we show the alignment process of the Schwarzchild-Chang telescope with wavefront measurement and the sensitivity table method. Wavefront is measured using the Shack-Hartmann sensor, and Zernike polynomials are obtained from measured wavefront. Sensitivity table method is to calculate alignment errors from the Zernike coefficients. As a result, we evaluate tilt, decenter, and despace of each mirror of linear astigmatism-free con-focal off-axis system.

• Journal of The Korean Astronomical Society
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• v.42 no.6
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• pp.175-184
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• 2009

A method of estimating the lower bound of coronal magnetic field strength in the neighborhood of an ejecting plasmoid is presented. Based on the assumption that the plasma ejecta is within a magnetic island, an analytical expression for the force acting on the ejecta is derived. The method is applied to a limb coronal mass ejection event, and a lower bound of the magnetic field strength just below the CME core is estimated. The method is expected to provide useful information on the strength of reconnecting magnetic field if applied to X-ray plasma ejecta.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.31.1-31.1
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• 2011

We present wide-field near-IR imaging polarimetry of 30 Doradus in the Large Magellanic Cloud, using the InfraRed Survey Facility (IRSF). We obtained polarimetry data in J, H, and Ks bands using the JHKs-simultaneous imaging polarimeter SIRPOL. Since many Galactic field stars along the line-of-sight to the Large Magellanic Cloud are contaminated in our data, we developed methods to identify the foreground sources using the proper motion data. We investigated polarimetric properties between the Galactic foreground stars and the stars in the LMC.

• Journal of the Korean Institute of Educational Facilities
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• v.15 no.5
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• pp.13-20
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• 2008

The sense of place at school environment becomes more important as children increasingly spend more time in school and children's attachment to the environment affects the cognition development of children. The goal of this research is to identify characteristics that enhance the sense of place for children in outdoor space and check the possibilities of forming it in the school environments. Through the analysis of design document and design report for schematic design of elementary school which is executed through Korean Institute of Educational Facilities between 2002-2005, 47cases from 32elementary schools are analyzed. As a result it is found that designers tend to orient towards the visual aspects compared to other invisible aspects such as thermal comfort and participation of children, which is extracted as a key characteristics of forming a sense of place for children. More attention is required to enhance the sense of place in school environment to support the child development in everyday space.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.6
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• pp.541-543
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• 2009

The masticatory space abscess caused by the acupuncture is a rare condition. A 27-year-old Korean man presented right buccal and submandibular space abscess induced by the acupuncture during his treatment of the temporomandibular disorder. The case was presented with review of literatures.