• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.165-168
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• 2002

This paper has been studied about the real time monitoring system development using TCP/IP ethernet and RS-422 serial communication link in general communication methods that rocket fire control agents could be monitoring about real time Rocket fire event procedures and be managing total rocket fire courses. Also, this paper has been studied the HMI(Human Machine Interface) control program and algorithm that guarantee confidential control for the Fire Display System.

• 한국정보통신학회논문지
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• 제17권5호
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• pp.1113-1118
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• 2013

오늘날 HTML5와 JavaScript를 활용한 하이브리드 웹 기반의 실시간 화상통신 기술이 대두되고 있다. 이에 본 논문에서는 HTML5를 지원하는 웹 브라우저를 이용한 실시간 화상통신 기술에 대해 연구하였다. HTML5와 JavaScript를 기반으로 시스템을 설계 및 구현하였으며, 서로 상이한 웹 브라우저들 간의 웹서버를 통해 RTC API와 HTTP/WebSockets 등을 사용하여 웹 브라우저를 활용한 실시간 화상통신을 가능하게 하였다. 이는 PC 및 노트북, 스마트패드, 스마트폰 등 모든 웹 브라우저의 사용 가능한 단말 기기로 사용 가능으로 별도의 회원가입이나 플러그인 등의 설치 없이 이용 가능하다. 이는 네트워크가 연결된 모든 환경에서 웹 브라우저의 이용이 가능한 모든 단말에서 사용가능하며, 제한적인 환경에서의 화상통신분야에 활용될 것이다.

• 한국멀티미디어학회논문지
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• 제24권2호
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• pp.199-207
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• 2021

It is very important to support real-time on the inspection equipment based on Windows. In particular, in the system using MIL-STD-1553B communication, which is widely used in military weapon systems, real-time is required for inspection equipment that uses mostly platforms based on Windows such as Industrial PCs. However, in order to use a complete real-time operating system such as VxWorks, the purchase cost is expensive and the implementation is complicated on the system, so it is not suitable for inspection equipment that requires simple functions to just check go or no-go. Therefore, in this paper, a Real-Time implanted Kernel(RTiK) in the Windows kernel is implanted in order to improve these defects, and real-time performance is implemented for periodically MIL-STD-1553B communication by Deferred Procedure Call(DPC) of Windows. Also, it was verified that the period of up to 2ms was guaranteed with a RDTSC into the EDX:EAX registers for measuring the periodicity.

• 한국통신학회논문지
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• 제38B권4호
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• pp.298-304
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• 2013

일반적으로 위성 시분할다중접속 (TDMA, Time Division Multiple Access) 통신시스템 설계 시 채널감쇄를 반드시 고려 해야하며 위성 통신시스템은 급격한 채널환경 변화에서도 안정적인 네트워크 구성을 위해 실시간 자동 이득제어기 (AGC, Automatic Gain Control)가 필수적이다. 본 논문에서는 위성 TDMA 통신시스템에서 타임 슬롯에 실시간 적용이 가능한 AGC를 제안한다. 제안하는 실시간 AGC 성능을 확인하기 위해 위성 TDMA 시스템을 설계 및 구현하였고 제안하는 AGC 알고리듬을 적용하여 시스템의 비트 오율을 확인하였다. 이 결과는 추후 위성 TDMA 통신시스템의 안정성을 높이는데 유용하게 활용될 수 있을 것으로 예상된다.

• International Journal of Internet, Broadcasting and Communication
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• 제13권1호
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• pp.134-142
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• 2021

This paper proposes a probabilistic method in analyzing timing measurements to determine the periodicity of real-time tasks. The proposed method fills a gap in existing techniques, which either concentrate on the estimation of worst-case execution times, or do not consider the stochastic behavior of the real-time scheduler. Our method is based on the Z-test statistical analysis which calculates the probability of the measured period to fall within a user-defined standard deviation limit. The distribution of the measured period should satisfy two conditions: its center (statistical mean) should be equal to the scheduled period of the real-time task, and that it should be symmetrical with most of the samples focused on the center. To ensure that these requirements are met, a data adjustment process, which omits any outliers in the expense of accuracy, is presented. Then, the Z-score of the distribution according to the user-defined deviation limit provides a probability which determines the periodicity of the real-time task. Experiments are conducted to analyze the timing measurements of real-time tasks based on real-time Linux extensions of Xenomai and RT-Preempt. The results indicate that the proposed method is able to provide easier interpretation of the periodicity of real-time tasks which are valuable especially in comparing the performance of various real-time systems.

• International Journal of Control, Automation, and Systems
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• 제3권4호
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• pp.591-600
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• 2005

In this paper, we discuss real-time control of networked control systems (NCSs) and practical issues in the choice of the communication networks for this purpose. An appropriate integration of control systems, real-time environments, and network communication systems allows the optimization of the quality-of-control (QoC) in NCSs. We compare several prevailing network types that may be used in control applications to offer a guideline of choosing a proper network. A real-time operating environment is also presented as an important ingredient of NCS design. To evaluate its feasibility and effectiveness, a real-time NCS containing a ball magnetic levitation (Maglev) setup is implemented via an Ethernet. Based on the experimental results, it is concluded in this paper that real-time control via Ethernet is a practical and feasible solution to NCS design.

• International Journal of Internet, Broadcasting and Communication
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• 제8권1호
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• pp.19-26
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• 2016

In this paper, the existing domestic HVAC systems, devices TCP / IP does not support the most, thereby, not performed remote management, it is necessary to regularly field service, inefficiency and cost bring a burden. This is through a comparison of the IoT-based primary, real-time protocol of what has become a hot topic recently, to be able to control and real-time monitoring through the CCU device in the HVAC system. Compare for this Internet of Things device for real-time monitoring and control of the XMPP, CoAP, MQTT main real-time protocol is used on. Finally, flexibility, light weight, based on MQTT a two-way messaging protocols with reliable message delivery, implements the protocol on the real-time HVAC system in the cloud platform.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권5호
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• pp.1733-1751
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• 2015

The IEEE 802.15.4 standard not only provides a maximum of seven guaranteed time slots (GTSs) for allocation within a superframe to support time-critical traffic, but also achieves ultralow complexity, cost, and power in low-rate and short-distance wireless personal area networks (WPANs). Real-time wireless body area sensor networks (WBASNs), as a special purpose WPAN, can perfectly use the IEEE 802. 15. 4 standard for its wireless connection. In this paper, we propose an adaptive GTS allocation scheme for real-time WBASN data transmissions with different priorities in consideration of low latency, fairness, and bandwidth utilization. The proposed GTS allocation scheme combines a weight-based priority assignment algorithm with an innovative starvation avoidance scheme. Simulation results show that the proposed method significantly outperforms the existing GTS implementation for the traditional IEEE 802.15.4 in terms of average delay, contention free period bandwidth utilization, and fairness.

• 한국정보전자통신기술학회논문지
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• 제11권1호
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• pp.26-33
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• 2018

A web application running on the Internet is causing many difficulties for a program developer, and it requires to process multiple sessions at the same time due to the occurrence of excessive traffic. Web applications should be able to process concurrent requests efficiently and in real time. Node.js is a single-threaded server-side JavaScript environment implemented in C and C ++ as one of the latest frameworks to implement event models across the entire stack. Nodes implement JavaScript quickly and robust to achieve the best performance using a JavaScript V8 engine developed by Google. In this paper, it will be explained the operation principle of Node.js, which is a lightweight real-time web server that can be implemented in JavaScript for real-time responsive web applications. In addition, this application was practically implemented through automatic alignment system for group scheduling to demonstrate event-based real-time response web processing.

• 한국전자통신학회논문지
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• 제1권1호
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• pp.20-26
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• 2006

최근에 급성장하고 있는 실시간 통신 분산 컴퓨팅은 최근에 컴퓨터 응용분야의 하나로서 컴퓨터 과학과 공학 분야에서 급성장하고 있는 한 분야이다. 실시간 객체 지향 분산 컴퓨팅은 분산된 컴퓨터 시스템에서 객체 네트워크의 형태로 구성된 실시간 분산 컴퓨팅이다. 본 논문에서는 TMO 구조를 이용하여 실시간 통신 시뮬레이션 프로그래밍을 하기 위해 DHS(Distributed High-Precision Simulation)라는 응용 환경에 적용하였다. TMO 구조에서 사용되는 시간 구동 및 메시지 구동 구조는 충분한 서비스를 제공하기 위해 데드라인 시간을 보장함으로서 실시간 시뮬레이션 프로그래머의 노력을 줄일 수 있는 이점을 가지고 있다. 데드라인 시간 보장은 프로그래머의 설계 시간을 처음 객체부터 적용하여 보장함으로서 형성될 수 있다. 분산된 객체지향 실시간 통신 시스템에서 TMO 구조를 이용한 다단계 프로그래밍 설계를 함으로서 실시간 통신 프로그래밍을 유연하게 작성할 수 있다.