• 제목/요약/키워드: Spread system

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방사성폐기물 통합 관리 시스템 (Radioactive Waste Integrated Management System)

  • 송덕용;최성수;한병섭
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2003년도 가을 학술논문집
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    • pp.572-578
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    • 2003
  • 본 발명은 비 접촉방식으로 데이터 정보를 인식하는 RFID(Radio Frequency Identification) 시스템과, 위성으로부터 정확한 시간과 거리를 측정하여 현 위치를 정확히 계산하는 GPS와, 이동통신 분야에서 많이 사용되고 있는 대역확산 기술인 CDMA를 이용하여 원자력발전소 임시저장소로부터 방사성폐기물 처분장까지의 전 과정을 방사성폐기물 개별 드럼 단위로 원격 감시할 수 있는 방사성폐기물 통합 관리 시스템이다.

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전자문서 활용을 통한 공공부문 사무관리체계 혁신 방안 (Improving Strategies for Public Office Management System through the Electronic Document Implementation)

  • 양정은
    • 한국컴퓨터정보학회논문지
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    • 제4권4호
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    • pp.236-243
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    • 1999
  • 정부를 비롯한 공공부문에 정보기술이 도입된 것은 어제 오늘의 일이 아니다. 그러나 정부에서 지금까지 하드웨어와 투입 중심으로 전개된 정보화의 영향력은 민간에 비해 빨리 실현되지 못하였고, 공공부문의 업무방식에는 근본적인 변화가 별로 나타나지 못했다. 이제 전자문서의 활용은 공공사무의 처리 및 업무의 능률성을 향상시키고 수작업 절차를 간소화함으로써 효율적인 관리를 가능하게 한다. 따라서 전자적 사무관리체계의 활성화를 위해 종이문서위주의 업무처리 관행의 축소, 전자문서화 촉진을 위한 기관 내적 기반 조성. 네트워크 연계를 통한 원격근무체계 등이 추진되어야 한다.

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대역 확산 통신방식에서 고속 주파수 호핑 시스템에 사용될 주파수 합성기의 실현에 관한 연구 (A Styudy on the Implementation of Frequency Synthesizer for the Fast Frequency Hopping Spread Spectrum Communication system)

  • 김원후
    • 한국음향학회지
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    • 제7권2호
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    • pp.51-64
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    • 1988
  • 고속 주파수 호핑 시스템을 구성하기 위해서는 무엇보다 천이 시간이 매우 짧은 주파수 합성기가 필요하다. 본 논물에서는 천이 시간이 수 nS 정도로 극히 짧은 직접 디지틀 주파수 합성기를 실현하고 그 특성을 실험하였다 또한 호핑 특성을 검토함으로써 본 논문에서 구성한 주파수 합성기가 고속 주파수 호핑 시스템에 적합함을 확인하였다. 마지막으로 현재의 기술수준으로 신호 대 잡음비 (SNR)를 획기적으로 증가시키고 아울러 시스템 구성을 간단히 할 수 있는 개선 방법을 제시하였다.

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페이딩 매질에서 대역확산 주파수도약 통신시스템의 전송특성 (Transmission Characteristics of FFH-SS Communication System in Fading Media)

  • 김원후;전계석
    • 한국음향학회지
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    • 제6권1호
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    • pp.5-14
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    • 1987
  • 이 논문은 시간 및 주파수 선택성페이딩이 동시에 존재하는 채널에서 대역확산 주파수 도약통신시스템의 전송특성을 제시한다. 수신기는 승적합산기를 포함한 binary noncoherent matched-filter fast FH-SS시스템이다. 이 시스템에서 SNR, 채널 선택도, 전력비 등의 변동에 따른 오차확률은 데이터율을 고려하지 않고 다이버시티 개념을 사용하여 구하였으며, 오차확율에 대한 데이터를 분석한 결과 FH-SS 시스템은 시간 선택성 페이딩 채널에서 전송특성이 우수함을 나타내었다.

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유비쿼터스 환경에서 OSGi를 이용한 상황인지 모바일 헬스케어 시스템 구현 (Implementation of Context-Aware Mobile Healthcare System Using OSGi in Ubiquitous Environments)

  • 송승재;류상환;장경수;신동렬
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.785-786
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    • 2006
  • Recently, Healthcare system has not been standardized and has been developed as an embedded system lacking interoperability. We are finally going to face such problems as having excessive load in using network caused by the uncontrolled spread of system and un-guaranteed interoperability among the heterogenous systems. We suggest the possibility that OSGi (Open Service Gateway initiative : the international standardization of service middleware) can be accepted as a solution for the above problems.

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A New Multicarrier Multicode DS-CDMA Scheme for Time and Frequency Selective Fading Channels

  • Cao Yewen;Tjhung Tjeng Thiang;Ko Chi Chung
    • Journal of Communications and Networks
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    • 제7권1호
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    • pp.13-20
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    • 2005
  • In this paper, a new multi carrier, direct sequence code division multiple access (MC-DS-CDMA) system is proposed. Our new signal construction is based on convolutional encoding of the transmitted data, serial-to-parallel (S/P) conversion of the encoded data, Walsh-Hadamard-transformation (WHT), a second S/P conversion of the WHT outputs, spread spectrum (SS) modulation with a common pseudo-noise (PN) sequence, and then multicarrier transmission. The system bit error rate (BER) performance in frequency selective fading channel in the presence of additive white Gaussian noise (AWGN) and a jamming tone is analyzed and simulated. The numerical results are compared with those from an orthogonal MC-DS-CDMA system of Sourour and Nakagawa [7]. It is shown that the two systems have almost the same BER performance, but the proposed scheme has better anti-jamming ability.

광시각용 LED 전광판제어 시스템 설계 (A Design of Large Area Viewing LED Panel Control System)

  • 이수범;남상길;조경연;김종진
    • 한국정보처리학회논문지
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    • 제6권5호
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    • pp.1351-1361
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    • 1999
  • The wide spread of multimedia system demands a large area viewing display device which can inform a message to many people in open area. This paper is about the design of a large area viewing LED panel control system. The control system runs on 16 bit microprocessor MC68EC000 and has following functions: 16 line clock and time, 2 channel priority interrupt, 2 channel direct memory access, 2 channel 12 bit clock and timer, 2 channel infrared remocon receiver, 2 channel RS-232C with 16 byte FIFO, IBM PC/AT compatible keyboard interface, ISA bus, battery backuped real time clock, battery backuped 256 byte SRAM and watch dog timer. The core circuits are implemented to ASIC, considering lower cost, higher reliability, higher performance, smaller dimension, and lower power consumption. This is verified by simulation and fabricated in 0.6 um CMOS SOG processes. The total gate count is 39,083 and the clock frequency is 48 MGz. The fabricated ASIC is mounted on test board.

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을지로 3가 지하철 ESS를 모의한 ESS 화재에서 Cell Balancing이 미치는 영향성 분석 (Analysis of the Cell Balancing Effect on the ESS Fire by Simulating the Euljiro 3-ga Subway ESS)

  • 윤상선;기석철
    • 전력전자학회논문지
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    • 제25권3호
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    • pp.219-226
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    • 2020
  • Given the change in the energy market, large energy storage systems (ESS) is rapidly entering the market. In this rapid spread, fire accidents are becoming an issue. This study attempts to approach the fire from the system point of view to analyze the problems caused by bonding from different perspectives. Moreover, to conduct this study, the fabrication of real objects is dangerous, which needs to be verified through simulation. In this study, we approach the cause of fire that occurs in large-capacity ESS from the system perspective. We focus on determining the effects of cell balancing performed on the BMS after charging. Thus, we analyze the cell balancing behavior and the linkage risks to the various stacks. The study also explores why no fire occurs during 70% operation.

Study on the Diversity Method to Improve the Performance of the CDMA System in the Mobile Wireless Channel

  • Lee Kwan-Houng
    • Journal of information and communication convergence engineering
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    • 제3권1호
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    • pp.1-4
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    • 2005
  • This study proposes a new diversity algorithm to improve the signal-to-noise ratio. In the wireless channel, if fading occurs due to the multipaths, the performance of the system is apparently reduced. One of the methods to reduce fadings like this is the diversity method, and this study aims to improve the performance of the system by proposing a new diversity algorithm. This study applied rake receiver, and normalized the wireless channel from the Nakagami fading channel to the Rayleigh fading channel, which set the fading index as 1, because of the multipaths. It applied QPSK and OQPSK modulation methods and applied the convolutional codes, where the code rate is 1/2 and 1/3 and the constraint length is 9, and the turbo code where the constraint length is 4. Under these conditions, this study compared and analyzed the average error probability of direct spread multiple access system. The diversity algorithm proposed in this paper could be applied to the mobile communication and other wireless multimedia communications that require high quality and high reliability.

단일톤 간섭제거를 위한 다단반송파 DS/DPSK 시스템의 성능분석 (Analysis of Multicarrier DS/DPSK Systems with Single Tone Interference Rejection)

  • 엄종선;김동인
    • 한국통신학회논문지
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    • 제22권4호
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    • pp.761-770
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    • 1997
  • Narrowband signals can be treated like a single tone interference at the receiver which demodulates wideband signals spectrum overlaid at the same frequency band. In this paper, the single tone interference is effectively suppressed by the use of a multicarrier DPSK direct-sequence(DS) spread spectrum(SS) with maximal-ratio(MR) combining instead of notch filter, which is hard to implement. A noncoherent DPSK system is considered because it is more realizable and does not require any complicate phase tracking, compared with a single carrier system subject to a constraint system bandwidth, and their performance comparisons are validated through simulation. We also propose a suboptimal-ratio(SR) combining which yields uniform and tight low bound on the performance of the MR combining, and then system parameters re optimized by theoretically evaluating the low bound, since an exact analysis appears intractable.

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