• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.92.1-92.1
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• 2011

NASA launched Solar Dynamics Observatory (SDO) on February 2011 in order to understand the cause of solar activities and their influences on the Earth and the near-Earth space. KASI is constructing Korean Data Center for SDO based on the letter of agreement between KASI and NASA for space weather research. SDO produces about 1.5 TB a day and its raw data amounts to about 550 TB in a year. Stanford University has been already operating the data center for scientific raw data, but there is a limit to use its data for space weather research and space weather service in real time because of network environment. Korean Data Center for SDO will provide scientific data not only to Korean institutes but also to international space weather societies. KASI has designed the data transfer system by using GLORIAD in order to get higher performance and stability. After the first construction of data transfer system and storage system in this year, we will increase the storage capacity of the data center in phases considering new developments in a storage technology and drop of their prices.

• Korean Journal of Crystallography
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• v.15 no.1
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• pp.9-17
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• 2004

There are 25 space groups in the trigonal system. Eighteen out of them have a lattice letter P displaying only hexagonal axes, wherease the remaining seven rhombohedral space groups R3(146), $R\={3}$(148), R32(155), R3m(160), R3c(161), $R\={3}m$(166) and $R\={3}c$(167) are described with two corrdinate systems, first with hexagonal axes having three lattice points (0, 0, 0), (2/3, 1/3, 1/3), (1/3, 2/3, 2/3) and second with primitive rhombohedral axes. In this paper, the space group $R\={3}c$ is discussed and the crystal structure of a compound, tris(1,2,3,4-tetraphenylbuta-1,3-dienyl)cyclotriphosphazene, $C_{84}H_{60}N_3P_3$, belonging to the space group $R\={3}c$ is elucidated with both hexagonal and rhombohedral cells.

• Archives of design research
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• v.17 no.4
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• pp.149-158
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• 2004

Domestic sign industry has seen a rapid growth in recent years, however, the level of quality is not so high. The main reason for this is due to the lack of well educated specialists. Thus, in this investigation, we will develop sign design experience software for the experienced employees in sign industry. Especially, focusing on the indoor letter information, we will develop the software that can provide the graphic effect associated with letter information. First, current situation and preliminary study in sign system used in public information were conducted, then design elements were analyzed from this. Then, experiments were performed on teh analyzed elements, and evaluation methods for the sign design were determined. Experiments including typography, color, layout, line alignment, letter space, and line space were conducted to analyze the visual perception. From these experiments, effective elements can be extracted and used as a elements for sign design software. As a next step, we will propose the development of experience software in sign design that can help to determine the sign elements. Thus, our investigation will provide sign design experience software that can be used by any inexperienced individuals, and be a great help for the more effective sign planning.

• Archives of design research
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• v.14 no.4
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• pp.199-207
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• 2001

The public performance of drama has essence to convert text to visual images as stage and to represent, inform such visual images. Visual image is formed through a space as stage. Stage is a dish to fill the texts and is the mother's womb of visual image. Namely, visual image of drama equals space image. The purpose of this study is a trial to grasp the structure and system represented through interpreting. Especially, the concerns of this study are not semiology of letter imported in image but spacial image text importing just contents of text and the process and contents grasping the structure and meaning of dramatic space. Finally, this study proposed 'the system of space embodiment'from the semiotic point of view as interpretation methodology of actual memorial, symbolic space.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.62.1-62.1
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• 2010

GMTO(Giant Magellan Telescope Organization) 이사회(Board Meeting)는 GMT의 1세대관측기기 1차 선정을 하였다. 의향서(Letter of Intent)를 제출한 12개 기기 중 9개 기기에 대해 제안서를 받아 과학자문위원회(Science Advisory Committee)에서 과학적 측면(Science), 기술적 측면(Technical), 비용 및 작업범위측면(Cost, scope & management)에서 심사한 결과 6개를 추천하였고 이사회에서 이를 승인하였다. 한국이 참여하는 GMTNIRS를 포함하여 G-CLEF, GMACS, GMTIFS, NIRMOS, TIGER가 선정되었다. 이 기기들은 2010년 4월부터 14개월 동안의 Conceptual Design Study를 거쳐 2011년 하반기에 이중에서 다시 3~4개가 GMT 1세대 관측기기로 최종 선정되어 제작될 예정이다.

• Journal of information and communication convergence engineering
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• v.6 no.3
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• pp.353-357
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• 2008

One objective in developing the next generation of wireless communication systems is to increase data rates and reliability. A promising way to achieve this is to combine multiple-input and multiple-output signal processing with a space-time coding scheme, which offers higher coding and diversity gains and improves the spectrum efficiency and reliability of a wireless communication system. It is noted, however, that time delay differences and phase differences among different channels increase symbol interference and degrade system performance. In this letter, we investigate phase differences and their effects on multiple-input and multiple-output systems, and propose a compensation algorithm for the Rayleigh fading model to minimize their effects.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.3
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• pp.304-306
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• 2016

In this letter, we investigate the performance of coherent free-space optical(FSO) systems under pulsed noise jamming conditions. In particular, we derive the average bit error probability of the coherent FSO systems with the pulsed noise jamming in a closed-form. Also, we derive the optimal fraction of symbol time of the jammer. We confirm the derived average error probability expressions by the exactly matching Monte-Carlo simulation results.

• ETRI Journal
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• v.28 no.5
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• pp.680-683
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• 2006

One objective in developing the next generation of wireless communication systems is to increase data rates and reliability. A promising way to achieve this is to combine multiple-input and multiple-output signal processing with a space-time coding scheme, which offers higher coding and diversity gains and improves the spectrum efficiency and reliability of a wireless communication system. It is noted, however, that time delay differences and phase differences among different channels increase symbol interference and degrade system performance. In this letter, we investigate phase differences and their effects on multiple-input and multiple-output systems, and propose a compensation algorithm for the Rayleigh fading model to minimize their effects.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.6C
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• pp.481-489
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• 2005

In this letter, we propose an efficient training sequence structure for adaptive linear multiuser detectors in space-time block coded multiuser systems, by exploiting a particular property of the minimum mean square error multiuser detectors used in these systems. The proposed structure wastes less overall system capacity than the straightforward training structure, without any corresponding loss of performance, as confirmed by the simulation results.

• ETRI Journal
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• v.34 no.5
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• pp.783-786
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• 2012

This letter proposes a more advanced joint maximum a posteriori (MAP) adaptation using a prior model based on a probabilistic scheme utilizing the bilinear transformation (BIT) concept. The proposed method not only has scalable parameters but is also based on a single prior distribution without the heuristic parameters of the previous joint BIT-MAP method. Experiment results, irrespective of the amount of adaptation data, show that the proposed method leads to a consistent improvement over the previous method.