• Title/Summary/Keyword: real-time network

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A Research to support Real-time of TAO on VxWorks Real-time Operating System (실시간 운영체제 VxWorks 상에서 통신 미들웨어 TAO의 실시간성 지원에 대한 연구)

  • Lim, jae-seok;Son, jae-yeol;Lee, yong-tae;Lee, cheol-hoon
    • Proceedings of the Korea Contents Association Conference
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    • 2009.05a
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    • pp.845-850
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    • 2009
  • To support distributed environment that is independent and standardized between heterogeneous system, a study on the TAO(The ACE ORB) communication middleware based on the RT-CORBA is highly being done. The TAO supports real-time features not on the general purpose operating system like Windows or Linux but on the real time operating system like Vxworks or LynxOS. In this paper, we build and construct environment that supports a thread-level real time feature by porting the TAO on VxWorks target. Also we validate the ported TAO by network communication with the TAO of Windows.

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A study on the extended TCP/IP protocol for real-time communication (실시간 통신을 위한 확장된 TCP/IP 프로토콜 개발에 관한 연구)

  • Yoon, Young-Chan;Park, Jae-Hyun
    • Journal of IKEEE
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    • v.2 no.1 s.2
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    • pp.42-52
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    • 1998
  • This paper proposes an extended TCP/IP protocol, LAN/TCP, that can be used for the distributed soft real-time systems connected through the Ethernet-based local area network. Since LAN/TCP shows soft real-time performance with keeping compatibility and interoperability with the standard TCP/IP, the existing application software can be used without any modification. LAN/TCP also provides the periodic transmission mode(PTM) with which the periodical data collection and updating the control signals can be efficiently implemented with relatively small traffic overhead. This paper includes the computer simulation and experimental results of the proposed protocol.

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A study on Design and Implementation of a Web-based real-time video communication system (웹 기반 실시간 화상 시스템 설계 및 구현에 관한 연구)

  • Ban, Tae-hak;Jeoung, Kyoung-Mo;Pyoun, Do-Kil;Jung, Hoe-Kyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.10a
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    • pp.712-714
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    • 2012
  • Using a web browser, real-time video communication technologies are emerging today. In this paper, we studied the web browser and take advantage of real-time video communication technology for Based on this, we have designed and implemented a Web-based real-time video communication systems. In this system, having different web browsers and web servers through a web browser using the RTC API and HTTP / WebSockets in a real-time video communication is possible. It is available at all terminals, all connected by a network environment from the use of the web browser, will be utilized in the field of visual communications in a limited environment.

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XML-Based Network Services for Real-Time Process Data (실시간 공정 데이터를 위한 XML 기반 네트워크 서비스)

  • Choo, Young-Yeol;Song, Myoung-Gyu
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.2
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    • pp.184-190
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    • 2008
  • This paper describes a message model based on XML (eXtensible Markup Language) to present real-time data from sensors and instruments at manufacturing processes for web service. HTML (Hyper Text Markup Language) is inadequate for describing real-time data from process control plants while it is suitable for displaying non-real-time multimedia data on web. For XML-based web service of process data, XML format for the data presentation was proposed after investigating data of various instruments at steel-making plants. Considering transmission delay inevitably caused from increased message length and processing delay from transformation of raw data into defined format, which was critical for operation of a real-time system, its performance was evaluated by simulation. In the simulation, we assumed two implementation models for conducting the transformation function. In one model, transformation was done at an SCC (Supervisory Control Computer) after receiving real-time data from instruments. In the other model, transformation had been carried out at instruments before the data were transmitted to the SCC. Various tests had been conducted under different conditions of offered loads and data lengths and their results were described.

Extension of ReInForM Protocol for (m,k)-firm Real-time Streams in Wireless Sensor Networks

  • Li, Bijun;Kim, Ki-Il
    • Journal of information and communication convergence engineering
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    • v.10 no.3
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    • pp.231-236
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    • 2012
  • For real-time wireless sensor network applications, it is essential to provide different levels of quality of service (QoS) such as reliability, low latency, and fault-tolerant traffic control. To meet these requirements, an (m,k)-firm based real-time routing protocol has been proposed in our prior work, including a novel local transmission status indicator called local DBP (L_DBP). In this paper, a fault recovery scheme for (m,k)-firm real-time streams is proposed to improve the performance of our prior work, by contributing a delay-aware forwarding candidates selection algorithm for providing restricted redundancy of packets on multipath with bounded delay in case of transmission failure. Each node can utilize the evaluated stream DBP (G_DBP) and L_DBP values as well as the deadline information of packets to dynamically define the forwarding candidate set. Simulation results show that for real-time service, it is possible to achieve both reliability and timeliness in the fault recovery process, which consequently avoids dynamic failure and guarantees meeting the end-to-end QoS requirement.

Prediction of Daily Water Supply Using Neuro Genetic Hybrid Model (뉴로 유전자 결합모형을 이용한 상수도 1일 급수량 예측)

  • Rhee, Kyoung-Hoon;Kang, Il-Hwan;Moon, Byoung-Seok;Park, Jin-Geum
    • Journal of Environmental Impact Assessment
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    • v.14 no.4
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    • pp.157-164
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    • 2005
  • Existing models that predict of Daily water supply include statistical models and neural network model. The neural network model was more effective than the statistical models. Only neural network model, which predict of Daily water supply, is focused on estimation of the operational control. Neural network model takes long learning time and gets into local minimum. This study proposes Neuro Genetic hybrid model which a combination of genetic algorithm and neural network. Hybrid model makes up for neural network's shortcomings. In this study, the amount of supply, the mean temperature and the population of the area supplied with water are use for neural network's learning patterns for prediction. RMSE(Root Mean Square Error) is used for a MOE(Measure Of Effectiveness). The comparison of the two models showed that the predicting capability of Hybrid model is more effective than that of neural network model. The proposed hybrid model is able to predict of Daily water, thus it can apply real time estimation of operational control of water works and water drain pipes. Proposed models include accidental cases such as a suspension of water supply. The maximum error rate between the estimation of the model and the actual measurement was 11.81% and the average error was lower than 1.76%. The model is expected to be a real-time estimation of the operational control of water works and water/drain pipes.

A Real-Time Messaging System for Twitter Users and Their Followers (트위터 사용자와 팔로워들 간의 실시간 메시지 교류 시스템 개발)

  • Park, Jong-Eun;Kwon, O-Jin;Lee, Hong-Chang;Lee, Myung-Joon
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.9
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    • pp.87-95
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    • 2011
  • Recently, as smartphones have rapidly come into wide use and various social networking services have grown, people perform a variety of interactions through the virtual and real world based on them. Usually, such services focus on easy formation of social links among users, supporting the exchange of simple messages among users on the networks. Twitter, one of such services used worldwide, supports short message service named Tweet and has over 200 million members signed up. n this paper, we propose techniques for supporting real-time group messaging based on the social network of Twitter and describe a smartphone group messaging system developed with the techniques. The system automatically forms a group that include a Twitter user and the followers of the user, supporting real-time group messaging among the group members. The developed system is composed of an XMPP protocol-based messaging server and smartphone client applications which perform real-time messaging based on the social network of Twitter. Twitter users can easily use the system utilizing Tweet messages, exchanging real-time messages with their followers within the groups instantly established on the XMPP server.

Performance Study on ZigBee-Based Wireless Personal Area Networks for Real-Time Health Monitoring

  • Koh, Bernard Kai-Ping;Kong, Peng-Yong
    • ETRI Journal
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    • v.28 no.4
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    • pp.537-540
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    • 2006
  • When multiple ZigBee wireless personal area networks (WPANs) are in close proximity to each other, contentions and collisions in transmissions will lead to increased packet delays. However, there is no existing study on how delay performance would be affected in a crowded real-life environment where each person walking down a busy street would be wearing a ZigBee WPAN. This letter studies the use of ZigBee WPANs in such a real-life environment for real-time heart beat monitoring. To be pragmatic, we derived a mobility pattern from the analysis of a real-life video trace. Then, we estimated the delay performance from the video trace by combining data collected from ZigBee experiments. The results show that the 300 ms packet delay requirement will not be met for only 11% of the time. When failure occurs, it will last for an average duration of 1.4 s.

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Building an SNS Crawling System Using Python (Python을 이용한 SNS 크롤링 시스템 구축)

  • Lee, Jong-Hwa
    • Journal of Korea Society of Industrial Information Systems
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    • v.23 no.5
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    • pp.61-76
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    • 2018
  • Everything is coming into the world of network where modern people are living. The Internet of Things that attach sensors to objects allows real-time data transfer to and from the network. Mobile devices, essential for modern humans, play an important role in keeping all traces of everyday life in real time. Through the social network services, information acquisition activities and communication activities are left in a huge network in real time. From the business point of view, customer needs analysis begins with SNS data. In this research, we want to build an automatic collection system of SNS contents of web environment in real time using Python. We want to help customers' needs analysis through the typical data collection system of Instagram, Twitter, and YouTube, which has a large number of users worldwide. It is stored in database through the exploitation process and NLP process by using the virtual web browser in the Python web server environment. According to the results of this study, we want to conduct service through the site, the desired data is automatically collected by the search function and the netizen's response can be confirmed in real time. Through time series data analysis. Also, since the search was performed within 5 seconds of the execution result, the advantage of the proposed algorithm is confirmed.

Adaptive Learning Control of Neural Network Using Real-Time Evolutionary Algorithm (실시간 진화 알고리듬을 통한 신경망의 적응 학습제어)

  • Chang, Sung-Ouk;Lee, Jin-Kul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.6
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    • pp.1092-1098
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    • 2002
  • This paper discusses the composition of the theory of reinforcement teaming, which is applied in real-time teaming, and evolutionary strategy, which proves its the superiority in the finding of the optimal solution at the off-line teaming method. The individuals are reduced in order to team the evolutionary strategy in real-time, and new method that guarantee the convergence of evolutionary mutations are proposed. It is possible to control the control object varied as time changes. As the state value of the control object is generated, applied evolutionary strategy each sampling time because of the teaming process of an estimation, selection, mutation in real-time. These algorithms can be applied, the people who do not have knowledge about the technical tuning of dynamic systems could design the controller or problems in which the characteristics of the system dynamics are slightly varied as time changes. In the future, studies are needed on the proof of the theory through experiments and the characteristic considerations of the robustness against the outside disturbances.