• Title/Summary/Keyword: digital communication systems

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A Study on the Application Method of Look-up Table to Color Printing Process (컬러인쇄공정에 대한 룩업테이블의 적용방법에 관한 연구)

  • 송경철;강상훈
    • Proceedings of the Korean Printing Society Conference
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    • 2000.12b
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    • pp.17-28
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    • 2000
  • Recently, as the prepress mainstream is changed to the digital workflow, various digital proofing systems such as high price dye sublimation printers and low price ink jet printers are widely used in printing industry. However, most of the digital proofing devices have lower resolutions than analog proofing systems and differ with actual color presses in the color gamuts. Therefore, proper color compensations are needed for digital color proofing in order to match color between the proofs and the press sheets. In this paper, we used 3-dimensional look-up table(LUT) and tetrahedral interpolation method for the color space conversion between the device independent color space(CIEXYZ or Lab) and the device dependent color space(CMY) to reduce the color differences between the original copy and digital color proofs and the press sheets.

Digital Hearing Aid DSP Chip Parameter Fitting Optimization (디지털 보청기 DSP Chip 파라미터 적합 최적화)

  • Jarng Soon-Suck
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.6
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    • pp.530-538
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    • 2006
  • DSP chip parameters of a digital hearing aid (HA) should be optimally selected or fitted for hearing impaired persons. The more precise parameter fitting guarantees the better compensation of the hearing loss (HL). Digital HAs adopt DSP chips for more precise fitting of various HL threshold curve patterns. A specific DSP chip such as Gennum GB3211 was designed and manufactured in order to match up to about 4.7 billion different possible HL cases with combination of 7 limited parameters. This paper deals with a digital HA fitting program which is developed for optimal fitting of GB3211 DSP chip parameters. The fitting program has completed features from audiogram input to DSP chip interface. The compensation effects of the microphone and the receiver are also included. The paper shows some application examples.

Voice Communication Performance in 900MHz ISM Band Using Codec2 (Codec 2를 이용한 900MHz ISM대역에서의 음성 통신 성능 검토)

  • Kim, Gyeong-Jin;Kim, Jeong-Uk
    • Journal of Korea Society of Industrial Information Systems
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    • v.23 no.6
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    • pp.59-66
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    • 2018
  • In this paper, we experimented how long distance voice communication is possible After implemented PTT(Push to talk) Bi-directional radio using open source project Codec 2, which is a low speed voice codec for digital amateur radio and 900MHz FSK transceiver. In case of a general digital radio, the AMBE+2 codec, which is regarded as an industry standard in terms of performance, is expensive and has the monopoly of technology. Using the 400MHz band in terms of frequency, narrow bandwidth of DMR(12.5kHz) and DPMR(6.25kHz) is used, so the data rate is low. In the 900MHz bandwidth can be extended, which is advantageous in terms of data transmission. As a result of the voice quality and distance field test, we could find that the communication takes place within about 500m. In this paper, only voice communication is reviewed. if a review of data transmission such as a simple image is added, this solution can be used in various fields as a low cost IOT radio.

Development of Power Line Communication based Home Network Message Specification and Systems for Digital White Goods (전력선 통신 기반의 디지털 백색 가전기기용 댁내망 메시지 규약 및 시스템의 개발)

  • Kim, Dong-Sung;Kwon, Wook-Hyun;Kim, Yo-Hi;Shin, Hyun-Jung;Yuh, In-Kwan
    • Proceedings of the KIEE Conference
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    • 2000.11d
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    • pp.709-711
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    • 2000
  • In this paper, a home network message specification and systems based on the Power Line Communication(PLC) are proposed. As a case study, the home network message specification and systems for the white goods are proposed. It is designed for the various home appliances from the lightning to the white goods using power line communication based on Internet protocol. The proposed home network system is composed of the home network message specification with browsing S/W and embedded H/W design based on the power line communication.

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The Development of the Data Error Inspection Algorithm for the Remote Sensing by Wireless Communication (원격계측을 위한 무선 통신 에러 검사 알고리즘 개발)

  • 김희식;김영일;설대연;남철
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.993-997
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    • 2004
  • A data error inspection algorithm for wireless digital data communication was developed. Original data converted By wireless digital data error inspection algorithm. Wireless digital data is high possibility to get distortion and lose by noise and barrier on wireless. If the data check damaged and lost at receiver, can't make it clear and can't judge whether this data is right or not. Therefore, by wireless transmission data need the data error inspection algorithm in order to decrease the data distortion and lose and to monitoring the transmission data as real time. This study consists of RF station for wireless transmission, Water Level Meter station for water level measurement and Error inspection algorithm for error check of transmission data. This study is also that investigation and search for error inspection algorithm in order to wireless digital data transmission in condition of the least data's damage and lose. Designed transmitter and receiver with one - chip micro process to protect to swell the volume of circuit. Had designed RF transmitter - receiver station simply by means of ATMEL one - chip micro processing the systems. Used 10mW of the best RF power and 448MHz-449MHz on frequency band which is open to public touse free within the limited power.

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Design and Implementation of Wireless Intelligent Controller for Micro-Inverter in Solar Power Systems (태양광 발전시스템에서 사용하는 마이크로인버터용 무선지능형제어기 설계 및 구현)

  • Han, Seongtaek
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.15 no.4
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    • pp.9-17
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    • 2019
  • Sun power generation systems which use large capacity centralized inverters have loss of power generation due to cloud and building shadows, pollution, cell deterioration, etc. To minimize loss of power generation, decentralized solar power systems using multiple micro-inverters are being proposed as an alternative. A distributed solar power system consisting of a system-connected system uses power line communication to collect data from the micro-inverters. Power line communication has the advantage of using power lines without separate lines for data transmission, but in distributed solar power generation systems that use a large number of micro-inverters, the bit error rate is less reliable due to the phenomenon caused by limited transmission power, high load interference and noise, variable signal attenuation, and impedance characteristics. So we proposed wireless intelligent controller for micro-inverter that is used to build distributed solar power systems. and we design and implement that. Further, the proposed wireless intelligent controller for micro-inverter was used to establish a small-volume solar power plant to check its function and operation.

A Study on the Expertment of Selective Frequency Hopping System (선택성 주파수 호핑 시스템의 실현에 관한 연구)

  • 정용주;김원후
    • Proceedings of the Korean Institute of Communication Sciences Conference
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    • 1987.04a
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    • pp.201-205
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    • 1987
  • In FH-SS systems when the bopping band is enough wide to onerlap with conventional band limited communication cethod (CBM). The portion of suchacts as an interfering signal. Thus it is gard to use them all together. This paper presents how the frequency gopping systems can simultaneously share the same band with CBM. The proposed mithod is that the frequency gopping band can arbitraily controlled by setting the specific input bith of digital frequency synthesizer to logical zero state We realized this by putting the hopping band Controller between pseudeo random generater and frequency synthesizer.

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Adaptive nonlinear compensation of digital communication channels using a volterra filter (볼테라 필터를 이용한 디지털 통신 채널의 적응 비선형 보상기법)

  • 김진영;최봉준;남상원
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.16-19
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    • 1996
  • The objective of this paper is to present a new adaptive nonlinear compensation method, which is based upon the Pth-order inverse theory and can be implemented in a systematic way, for weakly nonlinear systems that can be modeled by a Volterra series. In particular, employment of the proposed approach for the linearization of a given nonlinear system leads to the effective elimination of (up to a required order) nonlinearities in the overall system output. To demonstrate the feasibility of the proposed method, simulation results using a satellite communication system model are also provided.

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A Performance Comparison of Channel Estimation Methods for ISDB-T Systems (ISDB-T 시스템에서의 채널 추정기의 성능 비교)

  • Cho, Chang-Yeon;Kim, Joon-Tae
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.193-194
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    • 2008
  • In this paper, we compare the performance of the channel estimation methods with various interpolators for ISDB-T which is Japanese digital television terrestrial broadcasting systems. In this computer simulations, various interpolation methods are applied and the entire channel estimation performances according to the way of interpolation are compared.

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Wireless Digital Bit Stream Communication System Using AV Infrared Communication System (AV용 적외선 송수신장치를 이용한 디지털 비트스트림 무선 통신 시스템)

  • 최덕규;한찬호;홍영호
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2001.05a
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    • pp.217-223
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    • 2001
  • 본 논문에서는 기존의 AV용 적외선 송수신 시스템을 중간 매체로 이용하고, 그의 대역내에서 디지털 비트스트림을 고속으로 송수신할 수 있는 적외선 무선 데이터 통신 시스템을 제안 및 구현하였다. 제안한 시스템의 송신측에서는 디지털 비트스트림을 NTSC 비디오 신호 규격과 유사한 형태의 아날로그 신호로 변환하고, 이를 기존의 적외선 송신기로 무선 전송한다. 수신측에서는 기존의 적외선 수신기로 아날로그 신호를 수신하고, 이를 다시 디지털 비트스트림으로 변환한다. 본 논문의 결과는 다양한 AV시스템에서 적외선을 이용한 고속 무선 데이터 송수신에 응용될 수 있을 것이다.

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