• Title/Summary/Keyword: real-time communication

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Real-Time Marine Vehicle Management System (실시간 선박관리 시스템)

  • Syan, Lim Chia;Park, Soo-Hong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.7
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    • pp.995-1002
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    • 2013
  • In this paper, an effort has been made to design a Real-time Ship Management System where the status of a ship and its surrounding are constantly monitored and recorded at the base station. Proprietary system message based on overhead and checksum encapsulation has been designed to facilitate the communication. Software encoder and decoder are developed independently for each communication device attached to the system to process the proprietary system message into format by device standard. In addition, few configurations are designed to determine the method of updating the ship status message to the base station, which could be remotely chosen by the administrator.

Real-Time Communication using TMO(Time-Triggered and Message-Triggered Object) in Distributed Computing Systems

  • Kim, Gwang-Jun;Kim, Chun-Suk;Kim, Yong-Gin;Yoon, Chan-Ho;Kim, Moon-Hwan
    • Journal of information and communication convergence engineering
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    • v.1 no.1
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    • pp.12-22
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    • 2003
  • Real-time(RT) object-oriented(OO) distributed computing is a form of RT distributed computing realized with a distributed computer system structured in the form of an object network. Several approached proposed in recent years for extending the conventional object structuring scheme to suit RT applications, are briefly reviewed. Then the approach named the TMO (Time-triggered Message-triggered Object) structuring scheme was formulated with the goal of instigating a quantum productivity jump in the design of distributed time triggered simulation. The TMO scheme is intended to facilitate the pursuit of a new paradigm in designing distributed time triggered simulation which is to realize real-time computing with a common and general design style that does not alienate the main-stream computing industry and yet to allow system engineers to confidently produce certifiable distributed time triggered simulation for safety-critical applications. The TMO structuring scheme is a syntactically simple but semantically powerful extension of the conventional object structuring approached and as such, its support tools can be based on various well-established OO programming languages such as C++ and on ubiquitous commercial RT operating system kernels. The Scheme enables a great reduction of the designers efforts in guaranteeing timely service capabilities of application systems

Duplication Scheduling of Periodic Tasks Based on Precedence Constraints and Communication Costs in Distributed Real-Time Systems (분산 실시간 시스템에서 우선순위와 통신비용을 고려한 주기적 타스크들의 중복 스케줄링)

  • Park, Mi-Kyoung;Kim, Chang-Soo
    • Journal of Korea Multimedia Society
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    • v.2 no.4
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    • pp.378-389
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    • 1999
  • Parallel tasks in distributed real-time systems can be divided into several subtasks and be executed in parallel according to their real-time attributes. But, it is difficult to gain the optimal solution which is to allocate a tasks deadline into the subtasks deadline while minimizing the subtasks deadline miss. Tn this Paper, we propose the algorithm that allocates deadlines into each subtask, according to the attributes of each subtask(i.e. using communication time and execution time to periodic tasks). Also, we suggest a processor mapping algorithm that considers the communication time among the processors and the effective duplication algorithm which is allocated to the identical processor for the purpose of improving the communication time between the subtasks. We can obtain a result that reduces IPC(Inter-Processor Communication) time and uses the idle processor through applying effective real-time attributes to FUTD(Fully connected, Unbounded Task Duplication) algorithms. As a result, we can improve the average processor utilization.

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Study on Preemptive Real-Time Scheduling Strategy for Wireless Sensor Networks

  • Zhi-bin, Zhao;Fuxiang, Gao
    • Journal of Information Processing Systems
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    • v.5 no.3
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    • pp.135-144
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    • 2009
  • Most of the tasks in wireless sensor networks (WSN) are requested to run in a real-time way. Neither EDF nor FIFO can ensure real-time scheduling in WSN. A real-time scheduling strategy (RTS) is proposed in this paper. All tasks are divided into two layers and endued diverse priorities. RTS utilizes a preemptive way to ensure hard real-time scheduling. The experimental results indicate that RTS has a good performance both in communication throughput and over-load.

A Data Communication Method for Real-Time Control Systems (실시간제어시스템을 위한 데이터통신방식)

  • 장태무
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.7 no.2
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    • pp.66-70
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    • 1982
  • A data communication protocol and interface between a minicomputer and remote microprocessor-based real-time controllers are proposed and designed. Practically this method was implemented on a real-time data acquisition and on-line control system with a good performance.

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A Study of Automatic Measurement using Bluetooth Modem for Railway structures (블루투스 통신모뎀을 이용한 철도구조물의 자동계측에 관한 연구)

  • Lee, Seong-Won;Lee, Keun-Ho;Chung, Jae-Min
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.316-321
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    • 2006
  • The objective of this study is the developement of real time automatic datalogger using bluetooth modem for safety and maintence of civil construction sites. Automatic measurement system using general wireless modem is studied, and data communication method of between personal computer(or Server) and automatic measurement data is analyzed. Therefore data communication method and analyzing program of automatic measurement data is developed using real time automatic datalogger with bluetooth modem. The results of this study will be using real time automatic measurement of civil construction sites

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Performance Evaluation of Real-time Mechanisms for Real-time Embedded Linux (실시간 임베디드 리눅스의 실시간 메커니즘 성능 분석)

  • Koh, Jae-Hwan;Choi, Byoung-Wook
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.4
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    • pp.337-342
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    • 2012
  • This paper presents performance evaluation of real-time mechanisms for real-time embedded linux. First, we presents process for implementing open-source real-time embedded linux namely RTAI and Xenomai. These are real-time extensions to linux kernel and we implemented real-time embedded linux over the latest linux kernel. Measurements of executions of real-time mechanisms for each distribution are performed to give a quantitative comparison. Performance evaluations are conducted in kernel space about repeatability of periodic task, response time of Semaphore, FIFO, Mailbox and Message queue in terms of inter-task communication for each distribution. These rules can be helpful for deciding which real-time linux extension should be used with respect to the requirements of the real-time applications.

Composition of real-time robot workcell using token-bus

  • Kim, Dong-Jun;Kim, Kab-Il
    • 제어로봇시스템학회:학술대회논문집
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    • 1994.10a
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    • pp.251-256
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    • 1994
  • Integration of intelligent robot workcell is now a hot issue in CIM and robotics area. This piper dealt with relatively low-level essential topics, i.e., multi-robot coordination and real-time communication for the integration of intelligent robot workcell. For the coordination of multi-robot system, the tightly-coupled coordination is proposed using the various sensors. In order to handle the numerous communication data, time-critical communication network (Field-bus) is introduced and investigated. Finally, intelligent robot workcell is suggested using the Mini-MAP and Field-bus.

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Real-Time Communication of Periodic Messages on Wireless Sensor and Actor Networks (무선 센서-엑터 네트워크에서 주기적 메시지의 실시간 전송)

  • Ngo, Dao Quan;Lee, Sang-Jin;Kim, Myung-Kyun
    • Proceedings of the Korean Information Science Society Conference
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    • 2008.06d
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    • pp.291-296
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    • 2008
  • Wireless network technologies are becoming more widely used in industrial environment. The industrial communication system requires a real-time delivery of messages. The sensors periodically senses the physical environment and wants to deliver the data in real-time to the sink. This paper proposes a real-time protocol for periodic messages on wireless sensor and actor networks to be used in industrial communications. The proposed protocol delivers the data message using the shortest path from the source and the nearest actor. The protocol considers the energy consumption by reducing the number of broadcast messages during flooding. We have evaluated the performance of the proposed protocol using QualNet simulator. The simulation results show that the data messages have been delivered in real-time and the number of broadcast messages is reduced from 90% to 35% compared the existing protocols.

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Implementation of real time VJing responding to user's motion

  • Jung, Haehyun;Kim, Hyunggi
    • International Journal of Internet, Broadcasting and Communication
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    • v.7 no.2
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    • pp.41-50
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    • 2015
  • As various media have developed in modern society, frequency of use of interactive media has increased which makes interactive function that uses and handles projection mapping and LED screen in set design of broadcasting, concert, play, musical and EDM(Electronic dance music) in real time possible. Development of various media led today's viewers to have higher cultural desire and the need of various interactive performance contents to receive more attention.[1]. This thesis implemented real time VJing that responds to user's motion based on existing H/W by utilizing real time interactive elements.