• Title/Summary/Keyword: Communication Systems

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A Study on The Military Application of Commercial Mobile Communication Systems (상용 이동통신시스템의 군사적 활용에 관한 연구)

  • 김경식;권태환
    • Journal of the military operations research society of Korea
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    • v.27 no.2
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    • pp.110-123
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    • 2001
  • This paper deals with the application of commercial mobile communication system for improvement of the military mobile wireless communication systems. Currently, commercial mobile communication systems are rapidly growing from first and second Generation system to third and forth Generation system, which can provide multimedia service of high speed and high capacity(e.g., IMT-2000). If we adapt these emerging commercial technology for the military communication, the military will have many benefits in terms of cost saving, early operational deployment and performance. And it is possible to support the communication necessary in the future warfield operational environment. Therefore, we analyzed differences between commercial systems and military systems, and adaptability in terms of security, survivability and performance. Finally, we proposed a stepwise utilization scheme to improve the military mobile wireless communication

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SIMULATION IN AUTOMOBILE INFORMATION AND COMMUNICATION SYSTEMS

  • Takaba, Sadao
    • Proceedings of the Korea Society for Simulation Conference
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    • 1991.10a
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    • pp.41-77
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    • 1991
  • A large number of R & D projects in automobile information and communication systems have been achieved in these twenty years to improve various aspects on automobile usage. Examples on simulation for evaluation of these systems such as these on road to vehicle communication, inter-vehicle communication, and vehicle guidance are shown.

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Dimension Analysis of Chaotic Time Series Using Self Generating Neuro Fuzzy Model

  • Katayama, Ryu;Kuwata, Kaihei;Kajitani, Yuji;Watanabe, Masahide;Nishida, Yukiteru
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.857-860
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    • 1993
  • In this paper, we apply the self generating neuro fuzzy model (SGNFM) to the dimension analysis of the chaotic time series. Firstly, we formulate a nonlinear time series identification problem with nonlinear autoregressive (NARMAX) model. Secondly, we propose an identification algorithm using SGNFM. We apply this method to the estimation of embedding dimension for chaotic time series, since the embedding dimension plays an essential role for the identification and the prediction of chaotic time series. In this estimation method, identification problems with gradually increasing embedding dimension are solved, and the identified result is used for computing correlation coefficients between the predicted time series and the observed one. We apply this method to the dimension estimation of a chaotic pulsation in a finger's capillary vessels.

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Development of Interoperability Technology in Railway Wireless Communication Systems (철도 무선통신시스템 연동 기술 개발)

  • Cho, Woong;Cho, Han-Byeog
    • The Journal of the Korea institute of electronic communication sciences
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    • v.12 no.4
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    • pp.555-560
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    • 2017
  • Currently, railway wireless communication systems adopt several communication schemes depending on the specific region. To increase data rate and achieve high fidelity in railway wireless communication systems, LTE-R scheme has been developed. In this paper, We introduce interoperability technology which converges several railway communication systems including LTE-R. First, we consider two interoperability methods and their standardization. Some empirical test results of interoperability technology are also introduced. It is expected to provide seamless and statable railway communication environments by applying interoperability technologies to railway wireless communication systems.

Formal Verification and Performance Analysis of New Communication Protocol for Railway Signaling Systems (철도 신호시스템을 위한 새로운 통신 프로토콜의 성능해석 및 검증)

  • 이재호;황종규;박용진;박귀태
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.53 no.6
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    • pp.380-387
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    • 2004
  • In accordance with the computerization of railway signaling systems, the interface link between the signaling systems has been replaced by a digital communication channel. At the same time, the importance of the communication link has become increasingly significant. However, there are some questionable matters in the current state of railway signaling systems in KNR. First, different communication protocols have been applied to create an interface between railway signaling systems although the protocols have the same functions. Next, the communication protocols currently used in the railway fields have some illogical parts such as structure, byte formation, error correction scheme, and so on. To solve these matters, the standard communication protocol for railway signaling systems is designed. The newly designed protocol is overviews in this paper. And the simulation is performed to analysis the performance of data link control for designed protocol. According to this simulation, it is identified that the link throughput of new protocol is improved about 10% and the frame error rate is improved than existing protocol. And it is verified the safety and liveness properties of designed protocol by using a formal method for specifying the designed protocol. It is expected that there will be an increase in safety, reliability and efficiency in terms of the maintenance of the signaling systems by using the designed communication protocol for railway signaling.

Energy-Efficient Antenna Selection in Green MIMO Relaying Communication Systems

  • Qian, Kun;Wang, Wen-Qin
    • Journal of Communications and Networks
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    • v.18 no.3
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    • pp.320-326
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    • 2016
  • In existing literature on multiple-input multiple-output (MIMO) relaying communication systems, antenna selection is often implemented by maximizing the channel capacity or the output single-to-noise ratio (SNR). In this paper, we propose an energy-efficient low-complexity antenna selection scheme for MIMO relaying communication systems. The proposed algorithm is based on beamforming and maximizing the Frobenius norm to jointly optimize the transmit power, number of active antennas, and antenna subsets at the source, relaying and destination. We maximize the energy efficiency between the link of source to relay and the link of relay to destination to obtain the maximum energy efficiency of the system, subject to the SNR constraint. Compared to existing antenna selection methods forMIMO relaying communication systems, simulation results demonstrate that the proposed method can save more power in term of energy efficiency, while having lower computational complexity.

DEVELOPMENT OF ON-BOARD SOFTWARE FOR COMS GEOSTATIONARY OCEAN COLOR IMAGER

  • Park, Su-Hyun;Koo, Cheol-Hae;Kang, Soo-Yeon;Yang, Koon-Ho;Choi, Seong-Bong
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.257-259
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    • 2006
  • The Communication Ocean Meteorological Satellite (COMS) is a geostationary satellite being developed by Korea Aerospace Research Institute. Geostationary Ocean Color Imager (GOCI) is one of the payloads embarked on the COMS satellite. It acquires ocean images around Korea in 8 visible spectral bands with a spatial resolution of about 500 m. The acquired data are used to provide forecasting and now casting of the ocean state. The GOCI operations are controlled by the satellite embedded software, i.e. on-board software. This paper introduces the GOCI payload of the COMS satellite and describes the control software for the GOCI.

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