• 제목/요약/키워드: digital communication system

검색결과 2,536건 처리시간 0.032초

망막 두께 측정을 위한 32채널 영상획득장치 개발 (Development of 32-Channel Image Acquisition System for Thickness Measurement of Retina)

  • 양근호;유병국
    • 융합신호처리학회 학술대회논문집
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    • 한국신호처리시스템학회 2003년도 하계학술대회 논문집
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    • pp.110-113
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    • 2003
  • In this paper, the multi-channel high speed data acquisition system is implemented. This high speed signal processing system for 3-D image display is applicable to the manipulation of a medical image processing, multimedia data and various fields of digital image processing. In order to convert the analog signal into digital one, A/D conversion circuit is designed. PCI interface method is designed and implemented, which is capable of transmission a large amount of data to computer. In order to, especially, channel extendibility of images acquisition, bus communication method is selected. By using this bus method, we can interface each module effectively. In this paper, 32-channel A/D conversion and PCI interface system for 3-dimensional and real-time display of the retina image is developed. The 32-channel image acquisition system and high speed data transmission system developed in this paper is applicable to not only medical image processing as 3-D representation of retina image but also various fields of industrial image processing in which the multi-point realtime image acquisition system is needed.

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SCA Advice System: Ontology Framework for a Computer Curricula Advice System Based on Student Behavior

  • Phrimphrai Wongchomphu;Chutima Beokhaimook
    • Journal of information and communication convergence engineering
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    • 제21권4호
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    • pp.306-315
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    • 2023
  • This study proposed an SCA advice system. It is an ontology-based recommender that provides advice on appropriate computer curricula based on the behavior of high school students. The three computer curricula at Chiang Mai Rajabhat University include computer science (CS), information technology (IT), and web programming and security (WEB). This study aims to design the ontology framework for an SCA advice system. The system considers three core ontologies: student, computer-curriculum, and advice. After analyzing student behaviors, the behavior types of CS, IT, and WEB were determined to be SB-2, SB-1, and SB-5, respectively. All subjects in these three curricula were analyzed and grouped into seven groups. Their curricula were synthesized in terms of basic skills, basic knowledge, and characteristics. Finally, advice results can be obtained by consolidating the curriculum nature of the CS, IT, and WEB curricula.

LED 휘도의 디지털 제어 방식에 관한 연구 (A Study on Digital Control Method of LED Luminance)

  • 강신호;염정덕
    • 조명전기설비학회논문지
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    • 제24권1호
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    • pp.28-34
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    • 2010
  • 발광다이오드(LED)의 휘도를 제어하는 기존 방식은 펄스폭변조(PWM)방식이 주로 사용되었다. PWM 방식은 LED의 점등시간비와 휘도가 비례하는 아날로그적인 방식으로 통신 등의 디지털 방식과는 호환이 어려운 단점을 가지고 있다. 본 연구에서는 디지털 방식으로 적, 녹, 청색 LED의 휘도를 제어하는 실험을하였다. 이를 위해 LED 구동회로와 디지털 논리회로로 구성된 LED 디지털제어 장치를 개발하였다. 디지털 입력에 대한 적, 녹, 청색 LED의 점등 펄스 수를 제어하여 다양한 광색을 구현하고, 측정한 광색의 x, y 색도좌표가 원하는 색의 CIE 색도도 영역에 포함될 수 있도록 디지털 코드를 최적화시켰다. 본 연구 결과는 디지털 통신을 이용한 LED 램프의 원격 제어로 풀 컬러를 구현하는데 효과적으로 활용될 수 있다.

전자연동장치와 역정보전송장치간 인터페이스를 위한 데이터링크 프로토콜 성능해석 (Performance Analysis of Data Link Protocol for Interface between EIS and LDTS)

  • Hwang, Jong-Gyu;Lee, Jae-Ho
    • 한국철도학회논문집
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    • 제6권2호
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    • pp.135-141
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    • 2003
  • According to the computerization of railway signaling systems, the interface link between these signaling equipment is also replaced by digital communication channel, expecially communication link for interface between EIS and LDTS, but there are some problems in the present state of railway signaling. First of all, different communication protocol is applied to interface between above two signaling equipment although they have same functions. The other is that the communication protocol currently used in railway field has some unreasonable points such as structure, formation of byte, error correction scheme and etc. To solve these problems, the standard communication protocol for railway signaling is designed. The structure of designed communication protocol and the results of performance analyses are represented in this paper. It will be expected the increase of safety, reliability and efficiency of maintenance of signaling system by using of the designed communication protocol for railway signaling.

수중 초음파 통신을 위한 적응형 BPSK 복조기의 DSP 구현 (DSP Implementation of the Adaptive BPSK demodulator for Underwater acoustic communication)

  • 전재국;박찬섭;주형준;김기만
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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    • pp.109-110
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    • 2006
  • The performance of a digital baseband signal processing and data transmission rate depends on the modulation technique. In this paper, We implemented DSP communication system for Underwater acoustic communication using by adaptive BPSK modem technique. In order to implement adaptive modem, we suggested SNR detection block. SNR detection block has the reference SNR value that selects between window filter path and matched filter path. In this paper, suggested system is based on software interface and all Hardware(PLL, modem filter, equalizer etc) is implemented by software, exclusive of DSP, A/D, D/A converter, SDRAM and Flash memory.

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멀티미디어 통신망을 이용하는 원격교육 시스템 구성 (On the Organization of Distance Education System Utilizing Multimedia Communication Networks)

  • 송기상
    • 교육시설
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    • 제3권1호
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    • pp.19-30
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    • 1996
  • Integrated Services Digital Networks (ISDNs) and Broadband ISDN provide high speed data transmission capabilities and therefore, it is now possible to communicate with multimedia information including graphic, motion image, data and audio. Among several new services utilizing multimedia communication networks, distance education service which aims to overcome time and space restrictions between teachers and learners is now heavily focused in many countries. In this paper, several factors which affect to the effectiveness of distance education are surveyed and facilities for organizing distance education classrooms which utilize high speed multimedia communication network are studied in detail. Also, some points are suggested for organizing successful distance equation system based on the multimedia communication technology.

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변전자동화 클라이언트의 IEC 61850 기본 적합성 시험방안에 관한 연구 (A Study on the Basic Conformance test of IEC 61850 based Client)

  • 이남호;장병태;김병헌;심응보
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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    • pp.259-262
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    • 2009
  • IEC 61850 based substation automation system mainly consists of human machine interface and a various of IEDs in charge of protective and control functions of the substation. Both of them should require the performance verification of IEC 61850 communication services because their communication relation is the same as client and server throughout the digital network. This paper shows a research result on the testing method of basic communication interface of the IEC 61850 based client, which was implemented by the analysis of real communication between HMI and IED of IEC 61850 based substation automation system and refereed to IED IEC 61850 conformance test procedures.

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소형 무인해양탐사선 및 항법 개발 (Development of a Small Unmanned Marine Prober and Navigation)

  • 임종환;강철웅
    • 한국정밀공학회지
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    • 제21권3호
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    • pp.59-65
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    • 2004
  • The paper presents a small unmanned probing ship that can be used for acquiring information on marine and coastal environments. For communication system, we adopt direct and indirect methods based on the wireless modem of a commercial cellular telephone. The former is a direct communication between the modems of the ship and the server, and the latter is an indirect communication via internet between the ship and the server. The system is equipped with a digital compass and a GPS for position estimation, and extended Kalman filter is used for Navigation. The performance of the ship is demonstrated with the results produced by sets of experiments.

원자력 안전등급 제어기기의 통신망을 위한 통신보드 설계 (Design of Communication Board for Communication Network of Nuclear Safety Class Control Equipment)

  • 이동일;류광기
    • 한국정보통신학회논문지
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    • 제19권1호
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    • pp.185-191
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    • 2015
  • 본 논문에서는 원자력 안전등급 제어기기의 안전 통신망 구현을 위한 원자력 안전등급 통신 보드를 제안한다. 원자로 보호계통이 아날로그에서 디지털화되면서 디지털 통신망을 사용하게 되었다. 디지털 통신망은 원자력 안전등급에 사용되는 통신망으로 안전등급에서 요구하는 성능 및 시험을 통과한 통신보드가 제공되어야 한다. 통신 프로토콜 계층은 OSI 7 계층 중 물리계층, 데이터링크 계층, 어플리케이션계층만을 사용한다. 데이터 링크 계층에서는 사이버 보안을 위해 데이터 패키지를 변경하였다. 데이터 건전성을 위해 CRC32를 사용 하였으며 데이터 수신에 대해서는 재요청 및 응답을 하지 않는 단방향 통신만을 함으로써 원자력 안전계통에 영향을 주지 않게 설계 되었다. 또한 원자력안전등급을 획득하기 위해서 요건, 설계, 검증의 절차에 따라 설계하였다. 하드웨어검증을 위해 전자파 시험, 노화분석 시험, 육안검사, 번인시험, 내환경 시험 및 내진 시험과 같은 기기 검증을 수행 하였다. 또한 FPGA 펌웨어 검증을 위해 IEEE 1074의 생명주기를 준수하여 단위시험과 통합 시험을 실행 하였다[1-3].

Design of a Voting Mechanism considering Safety for Reliable System Using EPLD and Reliability Analysis

  • Ryoo, Dong-Wan;Lee, Hyung-Jik;Lee, Jeun-Woo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.40.2-40
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    • 2001
  • The protection system of the system communication, nuclear reactor and chemical reactor are representative of reliable system. This reliable system must be designed based on reliability as well as concept of safety, which is a failed system go a way of safe. Reliable system is composed of part of data acquisition, calculator, communication with redundancy, and a voter is important factor of reliability. Because it is serially connected. This paper presents a Design and Analysis of a Voting Mechanism considering Safety for reliable system Using EPLD. In the case of digital implementation a coincidence logic (voter) of reliable system, it needs CPU and memory, so increase a number of units. Therefore the failure rate and cost are increased on contrary when it is designed EPLD or FPGA.

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