• Title/Summary/Keyword: digital communication system

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A Case Study on Foreign Intelligent Transport System (지능형 교통 시스템의 해외 사례 연구)

  • Lee, Dong-Woo
    • Journal of Digital Convergence
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    • v.12 no.6
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    • pp.259-264
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    • 2014
  • Digital convergence means a service or new product which appeared through fusion of unit technologies in information and communication regions. In 2011, The Government introduced "IT Convergence Technology Prediction Survey 2025". Smart mobility is a main factor in smart city which is main example of convergence. A intelligent transport system(ITS) is a key factor of smart mobility. The conventional transport systems include road, car, signal systems. But the ITS is a transport system containing additional technologies such as electronics, control, communication to increase traffic safety and effectiveness of traffic facilities. In this paper, we described intelligent transport system related with our life.

Internet Based Remote Control and Monitoring System using Digital Timer (디지털 타이머를 이용한 인터넷 기반의 원격제어 및 모니터링)

  • Kim, E.J.;Kang, S.Y.;Bark, C.S.;Lim, Y.C.;Kim, G.W.
    • Proceedings of the KIEE Conference
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    • 2001.10a
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    • pp.245-248
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    • 2001
  • Recently, with the advancement of internet network the system has been needed to be controllable and observable through internet at industrial workplace. In this study, we developed the digital timer which has a communication function to control and observe many kinds of devices by combining relay and timer used for each type of control panel to realize control solution based on internet to be easily applicable at workplace with low cost and adding 485 serial communication module to have parallel expansibility and safety. And, this system was experimented and designed for easy system management and status check from remote station through internet. appling the developed digital timer to parallel sequence control of motor. As the result of experiment, the circuit configuration would be more simplified than the existing, and it is expected that multi-connection control and monitoring can be simply implemented with low cost equipment at industrial workplace.

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Internet Based Remote Control and Monitoring System using Digital Timer (디지털 타이머를 이용한 인터넷 기반의 원격제어 및 모니터링)

  • Kim, E.J.;Kang, S.Y.;Bark, C.S.;Lim, Y.C.;Kim, G.W.
    • Proceedings of the KIEE Conference
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    • 2001.10a
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    • pp.157-160
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    • 2001
  • Recently, with the advancement of internet network the system has been needed to be controllable and observable through internet at industrial workplace. In this study, we developed the digital timer which has a communication function to control and observe many kinds of devices by combining relay and timer used for each type of control panel to realize control solution based on internet to be easily applicable at workplace with low cost and adding 485 serial communication module to have parallel expansibility and safety. And, this system was experimented and designed for easy system management and status check from remote station through internet, appling the developed digital timer to parallel sequence control of motor. As the result of experiment, the circuit configuration would be more simplified than the existing, and it is expected that multi-connection control and monitoring can be simply implemented with low cost equipment at industrial workplace.

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Design Methodologies of High-speed Communication System with Signal Integrity (고속통신시스템의 신호충실성을 고려한 신호경로 설계 방법)

  • 박종대;박영호;남상식
    • Proceedings of the IEEK Conference
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    • 2000.11a
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    • pp.279-282
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    • 2000
  • As digital systems continue to use components with faster edge rates and clock speeds, transmission of the digital information in these systems approaches the microwave realm. At these speeds digital signal fidelity becomes both a critical success factor and design challenge. The noise sources in digital systems include the noise in power supply, ground and packaging media due to simultaneous switching of drivers, signal reflections and distortions on single and multiple transmission lines. This paper presents theory, case studies and design considerations of gigabit interconnection for network and communication systems. The case studies show HSPICE and Ampredictor simulations of alternate approaches. Various subjects including skin effect and dielectric losses, interconnect simulations and crosstalks of connector, affected signal discontinuity, are addressed.

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Design of the High Speed Variable Clock Generator by Direct Digital Synthesis (DDS 방식에 의한 고속 가변 클럭 발생기의 설계)

  • 김재향;김기래
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2000.10a
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    • pp.176-179
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    • 2000
  • The PLL synthesizer is used often in communication system due to several merits, such as broad bandwidth, high accuracy and stability of frequency. But it is difficult to use in current digital communication systems that need frequency hopping at a high speed because of its long frequency hopping time. In this paper, we designed frequency synthesizer that generate the clock frequency randomly at a high speed using the DDS technology and is applied to the pattern generator systemfor for digital image.

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Taining Kit for Xilinx FPGA or ALTERA CPLD Digital Logic Design with Center Bridge Chipset Architecture (중앙 브릿지 칩셋을 갖춘 Xilinx FPGA, ALTERA CPLD 겸용 Digital Logic Design Training kit)

  • 전상현;정완영
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.907-910
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    • 2003
  • We have developed Logic Design Training Kit for studying, actual training, designing of FPGA(Xillinx) or CPLD(ALTERA CPLD), the Digital Logic Device. This training kit has 12 matrix keys, RS232 port for serial communication and uses LED array. six FND(Dynamic), LCD as display part. That is standard specification for digital logic training kit. Special point of this kit is that we make two logic device trainig kit. This two logic device kit have more smaller and simple architecture because only uses one chip. That chip already includes a lot of functions that need for training kit, such as : complex logic circuit needed the two kind of logic devices, 16 way of system clock deviding function, serial communication interrupt....etc. We called that one chip is Center Bridge Chipset ; Xillinx FPGA Spartan2. User can select between using one device of FPGA or CPLD, or uses both them. Because of, Center Bridge Chipset has profitable architecture. it can work as Logic Device's networking with Master-Slave connection When using both logic devices.

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Equalizationof nonlinear digital satellite communicatio channels using a complex radial basis function network (Complex radial basis function network을 이용한 비선형 디지털 위성 통신 채널의 등화)

  • 신요안;윤병문;임영선
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.9
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    • pp.2456-2469
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    • 1996
  • A digital satellite communication channel has a nonlinearity with memory due to saturation characeristis of the high poer amplifier in the satellite and transmitter/receiver linear filter used in the overall system. In this paper, we propose a complex radial basis function network(CRBFN) based adaptive equalizer for compensation of nonlinearities in digital satellite communication channels. The proposed CRBFN untilizes a complex-valued hybrid learning algorithm of k-means clustering and LMS(least mean sequare) algorithm that is an extension of Moody Darken's algorithm for real-valued data. We evaluate performance of CRBFN in terms of symbol error rates and mean squared errors nder various noise conditions for 4-PSK(phase shift keying) digital modulation schemes and compare with those of comples pth order inverse adaptive Volterra filter. The computer simulation results show that the proposed CRBFN ehibits good equalization, low computational complexity and fast learning capabilities.

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Application Technology Development of Lon Works Fieldbus Network System for Distributed Control System Based Water Treatment Facility

  • Hong, Won-Pyo
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2004.05a
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    • pp.404-411
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    • 2004
  • 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 CPLD 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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AKA-PLA: Enhanced AKA Based on Physical Layer Authentication

  • Yang, Jing;Ji, Xinsheng;Huang, Kaizhi;Yi, Ming;Chen, Yajun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.7
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    • pp.3747-3765
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    • 2017
  • Existing authentication mechanisms in cellular mobile communication networks are realized in the upper layer by employing cryptographic techniques. Authentication data are broadcasted over the air in plaintext, enabling attackers to completely eavesdrop on the authentication and get some information about the shared secret key between legitimate nodes. Therefore, reusing the same secret key to authenticate several times results in the secret key's information leakage and high attacking rate. In this paper, we consider the most representative authentication mechanism, Authentication and Key Agreement (AKA), in cellular communication networks and propose an enhanced AKA scheme based on Physical Layer Authentication (AKA-PLA). Authentication responses generated by AKA are no longer transmitted in plaintext but masked by wireless channel characteristics, which are not available to adversaries, to generate physical layer authentication responses by a fault-tolerant hash method. The authenticator sets the threshold according to the authentication requirement and channel condition, further verifies the identity of the requester based on the matching result of the physical layer authentication responses. The performance analyses show that the proposed scheme can achieve lower false alarm rate and missing rate, which are a pair of contradictions, than traditional AKA. Besides, it is well compatible with AKA.