• 제목/요약/키워드: digital communication system

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MPEG-2 디지털 방송을 위한 송출 스케줄링 시스템 (A Scheduling System for MPEG-2 Digital Broadcasting)

  • 방진숙;황경민;정회경
    • 한국정보통신학회논문지
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    • 제12권2호
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    • pp.240-246
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    • 2008
  • 영상압축 기술의 발달로 인해 아날로그 영상은 디지털 신호로 표현 및 저장이 가능해졌고 MPEG-2 표준화 과정을 통해 디지털 영상 전송을 위한 표준이 제정되어 디지털 방송의 가능성이 제시되었다. 디지털 방송을 통한 경제적 파급 효과가 부각되면서 가치사슬의 기대효과로 인해 아날로그 방송 서비스를 제공하던 기존의 방송사업자들은 디지털 방송으로 서비스를 전환해 가고 있다. 그러나 종합유선방송사업자(SO : System Operator)들은 고화질의 디지털영상인 Full HD(High Definition)급 방송 프로그램의 확보에 어려움이 있어 디지털 방송 서비스에 난항을 겪고 있는 실정이다. 이에 본 논문에서는 주요 방송사에서 송출하고 있는 HD급 공중파 디지털 방송을 수신하여 PSIP(Program and System Information Protocol) 정보 분석을 통해 각각의 채널에 따른 디지털 방송 프로그램을 확보하고 이를 재편성하여 케이블 방송 가입자들에게 재전송할 수 있는 디지털 방송 송출 시스템을 설계 및 구현하였다.

드론 기술을 이용한 부력 조형물의 자세 제어 (Posture control of buoyancy sculptures using drone technology)

  • 강진구
    • 디지털산업정보학회논문지
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    • 제14권4호
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    • pp.1-7
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    • 2018
  • The floating sculptures in the form of ad-ballon commonly used ropes in order to hold on. Relatively air flow is much less indoor than outdoor. Users of buoyancy sculptures hope to be able to maintain their desired posture without being fixed. This study applied drone technology to buoyancy sculptures. The drones can be moved vertically and horizontally, and the posture can be maintained, so buoyancy sculptures are easy to apply. Therefore, we have studied the control system of buoyancy sculpture using drone technology. Also, a control system that can maintain the desired posture at a constant height was studied. The overall shape was a light fiber material and helium gas for zero buoyancy to support the sculpture. The system configuration was STM32F103CB from ARM. In addition, the gyro and acceleration, geomagnetic sensors and motors are composed of small and medium size BLDC motors. The scheduling of the control system in the configuration of the control device was carefully considered. Because the role of the whole component becomes very important. The communication between the components is divided into the sensor fusion and the interface communication with the whole controller. Each communication technology is designed to expand. This study was implemented to actively respond from the viewpoint of posture control using the drone technology.

스마트 팩토리에서 설비 장애 진단 및 조치 시스템 구조 (A System Architecture for Facility Fault Diagnosis and Repair Action in Smart Factory)

  • 조재형;이재오
    • KNOM Review
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    • 제23권1호
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    • pp.18-25
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    • 2020
  • 최근 스마트 팩토리(Smart Factory)에 대한 연구는 단순히 공장 자동화(Factory Automation, FA)의 개념에서 데이터를 수집하고 분석하는 형태로 발전하고 있다. 이것은 통신 기술의 발전(5G)과 IoT 장치(device)들이 현장 상황에 맞춰 다양하게 개발되면서 가속화 되고 있다. 또한, 기업 경쟁력 강화로 디지털트랜스포메이션(Digital Transformation)이 활발히 이루어지고 있으며, 이를 각종 IoT 장비로 부터 수신한 데이터와 자동화된 설비를 결합시켜 공정 재조정을 통한 최적화 연구가 다양하게 진행되고 있다. 따라서 본 논문에서는 관련 연구 중 하나인 예측 시스템을 활용한 설비 장애 진단 및 조치 시스템 구조 및 요소를 제안한다.

Control and Development of LonWorks Intelligent Control Module for Water Treatment Facility Based Networked control System

  • Hong, Won-Pyo;Kim, Dong-Hwa
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1757-1762
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    • 2003
  • With distribution industrial control system, the use of low cost to achieve a highly reliable and safe system in real time distributed embedded application is proposed. This developed intelligent node is based on two microcontrollers, one for the execution of the application code, also as master controller for ensuring the real time control & the logic operation with PLD and other for communication task and the easy control execution, i.e., I/O digital input, digital output and interrupting. This paper also presents where the case NCS (Networked control system) with LonTalk protocol is applied for the filtration process control system of a small water treatment plant.

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Design and Implementation of a SDR-based Digital Filter for CDMA Systems

  • Yu, Bong-Guk;Bang, Young-Jo;Kim, Dae-Ho;Lee, Kyu-Tae;Ra, Sung-Woong
    • Journal of Ubiquitous Convergence Technology
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    • 제2권2호
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    • pp.59-66
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    • 2008
  • In this study, Software Defined Radio (SDR) technology-based digital filterbank architecture applicable to a multiple-channel processing system such as a wireless mobile communication system using Code Division Multiple Access (CDMA) technology is proposed. The technique includes a micro-processor to redesign Finite Impulse Response (FIR) filter coefficients according to specific system information and to download the filter coefficients to one digital Band Pass Filter (BPF) to reconfigure another system. The feasibility of the algorithm is verified by computer simulation and by implementing a multiple-channel signal generator that is reconfigurable to other system profiles, including those of a Wideband Code Division Multiple Access (WCDMA) system and a CDMA system.

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디지털 PLL을 이용한 ATS 지상자 코일 Q 측정장치 개발 (Q Factor Measurement System for a ATS Coil Using Digital Phase Locked Loop)

  • 김기택;임기택;최정용;김봉택
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2000년도 춘계학술대회 논문집
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    • pp.368-375
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    • 2000
  • For safety reason ATS(Automatic Train Stop) system is being used, which is a kind of communication system with a feedback amplifier and a transformer on the train and wayside coils. The coils are highly resonant LC circuits, also have very high Q(Quality) factors. The Q factors of wayside ATS coils are to be maintained high enough for the amplifier to operate reliably. In this paper a novel Q measurement system is proposed. The system measures the resonant frequency and the bandwidth of the ATS coils, by controlling the phase difference between the transformer and the coil using digital PLL(Phase Locked Loop). The overall configuration and algorithms of the proposed system and the digital PLL control schemes are presented in details. The experimental waveforms are shown to verify the system performances.

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Implementation of Process System and Intelligent Monitoring Environment using Neural Network

  • Kim, Young-Tak;Kim, Gwan-Hyung;Kim, Soo-Jung;Lee, Sang-Bae
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제4권1호
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    • pp.56-62
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    • 2004
  • This research attempts to suggest a detecting method for cutting position of an object using the neural network, which is one of intellectual methods, and the digital image processing method. The extraction method of object information using the image data obtained from the CCD camera as a replacement of traditional analog sensor thanks to the development of digital image processing. Accordingly, this research determines the threshold value in binary-coding of an input image with the help of image processing method and the neural network for the real-time gray-leveled input image in substitution for lighting; as a result, a specific position is detected from the processed binary-coded image and an actual system designed is suggested as an example.

웹 기반 비동기/동기 사회활동을 지원하는 협력 시스템 (A Cooperation System Supporting Web-based Asynchronous/Synchronous Social Activities)

  • 최종명;이상돈;정석원
    • 디지털산업정보학회논문지
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    • 제5권2호
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    • pp.39-49
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    • 2009
  • In this paper, we classify web-based social network into two types: open and community, and model user behavior in social activities. After that, we also propose the combination of instant messaging and web system as the method of support asynchronous/synchronous social activities. Furthermore, we introduce ImCoWeb prototype system that supports both asynchronous social activities (ex. social bookmark, comment, rate, and data share) and synchronous ones (ex. real-time communication, file transfer, co-browsing, and co-work). Because it is built on the existing instant messaging, it reduces costs by reusing the facilities such as session management, user management, and security of instant messaging.

Design and Implementation of a Duplex Digital Excitation Control System for Power Plants

  • Nam. Chae-Ho;Nam, Jung-Han;Choi, June-Hyug;Baeg, Seung-Yeob;Cho, Chang-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.140.4-140
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    • 2001
  • This paper presents the duplex controller operated as master slave for Self Excited Static Type excitation system and the results of operation for duplex digital excitation system. Software is made up duplex multi-tasking control algorithm which is based on VxWorks(real-time OS), preprocessing algorithm for input-output signal, BSP & Device Driver for interfacing hardware and software, and OIS(Operator Interface Station) program, HMI S/W. Master controller and slave controller intercommunicate dominant data to minimize bump when controller switchover from master to slave occurs. Communication between master controller and slave controller is duplicated and communication between OIS and controller is duplicated. Hardware is made up VMEBUS based controller which is designed with PPC & I/O board ...

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멀티미디어 통신 그리드의 설계 및 구현 (Design & Implementation of a Multimedia communication Grid)

  • 김일민
    • 디지털콘텐츠학회 논문지
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    • 제8권1호
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    • pp.27-33
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    • 2007
  • 그리드(Grid)는 WWW 컴퓨팅 모델을 계승할 차세대 분산 처리 모델이며, 자바 언어는 그리드 시스템을 설계하고 구현하는 훌륭한 개발 언어이다. 자바언어는 분산 처리를 위해 개발되었으며, 현재 WWW 응용 개발에 널리 사용되고 있다. 본 논문에서는 그리드의 기본 개념을 소개하고, 자바 언어를 사용한 컴퓨팅 그리드를 설계하고 구현하였다. 구현된 컴퓨팅 그리드에 알맞은 분산 응용 프로그램의 실행 결과를 분석하였다. 본 논문에서 구현된 그리드에 사용된 분산 멀티미디어 응용의 실행 결과는 기존의 시스템에 비하여 매우 향상된 성능을 보여주고 있다.

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