• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.545-548
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• 2017

This study describes the design and implementation of IFA(Input Filter Assembly) for Digital Satellite Communication. The IFA unit for SHF band consists of coupler, LPF(Low Pass Filter) and input Filter. Through the pre-simulation analysis of space environment, the possibility of the malfunction of equipment minimized and we designed a reliable IFA through simulation for vibration analysis generated during the launch, and compared pre-simulation of main performance results to test results about main performances of IFA after production.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.4
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• pp.105-118
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• 2007

The purpose of this study is not only to compare between 'Opened Landscape' and 'Filtered Landscape' image and preference but also to suggests a guide line of planting design for progressive realization. For this, the image structures of photo-sketch simulation for parallax landscape have been investigated by Semantic Differential scale(S.D. scale) and the Factor analysis. The results could be summarized as follows. The results of S.D. scale values for landscape through parallax were greater than non-parallax landscape. The scenes through parallax were better preferred to direct view. Thus the results of photo-sketch simulation test support the expected hypothesis that the visual environment of complexity and variety is closely correlated with the parallax effect and monotonous or non-parallax environment, and parallax effect on close view more bigger than the distant view. Factors covering the spatial image of parallax landscape were found to be seven and Total values were 60.35 %. The most important factors determining the parallax effect were Factors I 'depth of space' and VI 'expectation of space and interest'. An outstanding view must be handled properly to be preserved or accentuated. In this sense, the parallax spatial beauty with tree could be improved through the visual aspects of plan arrangements and the progressive realization appeared to be one effective design technique for landscape planning and design.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.9-14
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• 2018

This study describes the design and implementation of IMUX(Input Multiplexer) for Satellite Communication. The IMUX unit for SHF band consists of Combine Filter, Power Splitter, Isolator and Channel Filter. Through the pre-simulation analysis of space environment, the possibility of the malfunction of equipment minimized and we designed a reliable IMUX through simulation for vibration analysis generated during the launch, and compared pre-simulation of main performance results to test results about main performances of IMUX after production.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.983-988
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• 2017

This study describes the design and implementation of OMUX(Output Multiplexer) for Satellite Communication. The OMUX unit for SHF band consists of LPF(Low Pass Filter), manifolder and Channel Filter. Through the pre-simulation analysis of space environment, the possibility of the malfunction of equipment minimized and we designed a reliable OMUX through simulation for vibration analysis generated during the launch, and compared pre-simulation of main performance results to test results about main performances of OMUX after production.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.5
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• pp.8-15
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• 2010

Besides its basic function of illuminating a space, lighting can greatly affect the efficiency of a space when an advanced technology and planning, together with the effects of various presentations, are applied to lighting. A lighting plan suitable for maximizing the efficiency of a space will only be made feasible by considering the location of a space and the characteristics of the lamps to be used. In particular, the lighting plan for a space with a special function requires prior investigation and analysis of that space. In this study, the feasibility of a lighting environment for the tunnel of a radioactive waste disposal facility is investigated via a prior lighting design and simulation, which take into account the spatial characteristics of the tunnel. For this study, the use of fluorescent induction lamp is suggested, and the standards of lighting plan and structure are followed depending on the location of each segment of the tunnel. Then, a simulation analysis is conducted to investigate the feasibility of the plan.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.11
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• pp.1617-1624
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• 2013

This paper analyzes the relation between fire shutters and fire spread by conducting fire simulation on inner space with fire shutters. Using Fire Dynamics Simulator (FDS), a commercial fire simulation software, the simulation is done on an ideal inner robby, where fire size and the open/close of fire shutters are varied. Our simulation environment can derive significant fire parameters such as temperature variation of fire room walls and entrances of refuge stairs, variation of carbon dioxide, and soot spread. According to the simulation results, temperature and carbon dioxide distribution in refuge stairs have little dependence on vent open or close, but the part close of fire shutters blocks soot inflow to refuge stairs.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.4
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• pp.335-342
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• 2023

Lunar Navigation Satellite System refers to a constellation of satellite providing PNT services on the moon. LNSS consists of main satellite and navigation satellites. Navigation satellites orbiting around the moon and a main satellite moves the area between the moon and the L2 point. The navigation satellite performs the same role as the Earth's GNSS satellite, and the main satellite communicates with the Earth for time synchronization. Due to the effect of the non-uniform shape of the moon, it is necessary to focus on the influence of the lunar gravitational field when designing the orbit simulation for navigation satellite. Since the main satellite is farther away from the moon than the navigation satellite, both the earth's gravity and the moon's gravity must be considered simultaneously when designing the orbit simulation for main satellite. Therefore, the main satellite orbit simulation must be designed through the three-body problem between the Earth, the moon, and the main satellite. In this paper, the orbit simulation tool for main satellite and navigation satellite required for LNSS was designed. The orbit simulation considers the environment characteristics of the moon. As a result of comparing long-term data (180 days) with the commercial program GMAT, it was confirmed that there was an error of about 1 m.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8A
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• pp.775-783
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• 2006

In this paper, the new technique combining beamforming with space-time coding is proposed for an orthogonal frequency division multiplexing(OFDM) system with multi-input multi-output(MIMO). When MIMO-OFDM system is employing Nt(the number of transmitterantenna) beamfomers and one S-T decoder at Nr receiver antennas, Nt signals removed CCI are outputted at the beamformer and then diversity gain can be got through space-time decoding. As the proposed technique can reduce cochannel interference and get diversity gain in the multi-user environment, the performance of MIMO-OFDM system is very improved. BER performance improvement and convergence behavior of the proposed approach are investigated through computer simulation by applying it to MIMO-OFDM system in the multi-user environment.

• The Journal of the Korea Contents Association
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• v.3 no.3
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• pp.19-33
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• 2003

Computer simulation has used to a area of military training from about several years ago. War game mode(or computer simulation) endow a military man with lied training such as combat experience without operating combat strength or capabilities. To sanely construct simulation environment against actual combat environment associate among federates on network. us construct virtual combat environment enabling to efficiently manage network traffic among federates(or active nodes) by using active network technique on virtual military training space such as urgent combat field needed to rapidly transfer combat information including image and video, verify its validity by the help of simulation

• Journal of the Korean Solar Energy Society
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• v.40 no.1
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• pp.35-47
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• 2020

Due to the large window area, the lighting environment of the educational space between the window and deep part of the room is not uniformly illuminated, and the phenomenon of glare is severe. For this reason, the daylight performance of DSC-BIPV windows was analyzed in order to improve the natural lighting in the educational sector. The method derives the correlation with natural lighting by measurement and simulation. Dynamic simulation confirmed that the average illuminance of the target space was higher at later than the early afternoon. The performance of natural lighting at 40% and 30% transmission of DSC has the effect of significantly reducing the amount of excess light in existing windows. Nevertheless, the actual average illuminance in all seasons corresponds to the standard illuminance of the educational facility, 300 Lux. In addition, the uniformity is also seen through the skylight illuminance ratio.