• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.11
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• pp.1631-1636
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• 1989

A space charge model for semiconductor reduced gas sensors has been roposed and applied to gas sensing mechanism. SnO2-x and SnO2-x/Pt thin film were deposited by vacuum evaporating method. And Hall effect and gas sensitivity characteristics of these sensors were measured. From the space charge model and carrier concentration, the number of the adsorbed gas atom on the solid surface was calculated quantitatively. The gas sensing model was compared with CO gas sensitivities of the fabricated thin film gas sensors.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.274-277
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• 2004

KSLV (Korea Space Launch Vehicle)-I telemetry system will be composed of two telemetry streams: a lower stage telemetry stream and an upper stage telemetry stream. In this paper, the authors present design, implementation and test results of the upper stage telemetry interface for KSLV-I. The telemetry system currently is in the stage of the prototype model development, and its engineering model and flight model will be developed in the near future.

• Journal of Power Electronics
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• v.11 no.5
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• pp.662-668
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• 2011

This paper presents an analysis of a 4th order LCLC resonant converter with a capacitive output filter using the state-space approach. The analysis of the converter shows that there are four intervals in a half period. In each interval, the state-space equations are obtained. Due to the soft switching of the converter, an exact equation for the Zero Voltage Switching (ZVS) time and the maximum dead time of the inverter switches are presented. The simulation and experimental results obtained from a 10kv, 370w prototype confirm the validity of the theoretical analysis.

• Bulletin of the Korean Space Science Society
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• 2007.10a
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• pp.64-64
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• 2007

• The Bulletin of The Korean Astronomical Society
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• v.25 no.1
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• pp.54-54
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• 2000

• Journal of Communications and Networks
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• v.14 no.2
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• pp.206-212
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• 2012

In this paper, in order to effectively apply unitary space-time modulation to the direct-sequence spread-spectrum multiple-access (DSSS-MA) networks, we propose a low-rate, noncoherent, unitary, and space-time modulated DSSS system supporting any number of transmit antennas based on Walsh matrices. The proposed scheme simultaneously performs bandwidth spreading and space-time coding and outperforms those using high-rate, conventional unitary space-time constellations. Furthermore, the proposed scheme allows for a simple detector structure based on fast Walsh transforms.

• Electronics and Telecommunications Trends
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• v.38 no.2
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• pp.85-95
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• 2023

Space optical communication technology capable of large-capacity, high-speed, and low-latency communication can reduce the size, weight, and power consumption of radio frequency communications in existing satellite systems, thereby reducing launch costs, accommodating additional science instruments, and extending lifetime. Despite the high technical difficulty, various projects are being carried out in advanced countries regarding space technology for use in national security and defense, earth observation, and space communications. We review the advantages, key components, and development trends of space optical communication technology, which is attracting attention in applications such as satellite communications, intersatellite linking, and deep space communications.

• Bulletin of the Korean Space Science Society
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• 2000.04a
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• pp.38-38
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• 2000

No Abstract, See Full Text

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.58-58
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• 2004

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.341-345
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• 2006

The GPS is widely used in various parts, therefore it is required higher integrity and continuity. These integrity and continuity are threatened by outer jamming signals which are intended or not. And various anti-jamming ways have been studied to remove these jamming signals. In this paper, we are going to test the efficiency of the anti-jamming algorithm in space and time-space domain, and analyze