• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.128-129
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• 2019

ITER AC/DC Converter는 플라즈마 운전에서 기능적인 역할과 동작 모드에 따라 PF/CS, TF, CC Plant로 구분되어 동작하며 PF, CS, VS1 컨버터는 플라즈마 전류 발생, 증감, 형상제어, 위치제어를 하며 PCS(Plasma Control System), MRC(Master Controller)에 의해 제어된다. MRC는 상위 제어인 PCS와 LCC(Local Control Cubicle)의 Middle Ware Layer에서 여러 Linux Machine들과 복잡한 통신망으로 연결되어 초전도 코일 전류 Driver에 있어서 Control과 Soft Down을 위한 Real Time 제어 기능을 한다. 본 논문은 이러한 제어를 구현하기 위한 Linux Real Time Control Thread Design의 구성과 결과를 논의하고자 한다.

• IEMEK Journal of Embedded Systems and Applications
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• v.16 no.6
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• pp.247-251
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• 2021

We propose a protocol for Ethernet-based industrial real-time communication networks. In the protocol, the master periodically transmits control frames to all slaves, and the ring-type network topology is selected to achieve high-speed transmission speed. The proposed protocol is implemented in the form of both firmware and Linux kernel modules. To improve the transmission speed, the MAC address table is disabled in the firmware implementation, and the NAPI function of the Ethernet driver is removed in the Linux kernel module implementation. A network experiment environment is built with four ARM processor-based embedded systems and network operation experiments are performed for various frame sizes. From the experimental results, it is verified that the proposed protocol normally operates, and the firmware implementation shows better transmission speed than the Linux kernel module implementation.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.6
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• pp.393-400
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• 2011

Recently, demands of information devices are increasing as we can find so many information devices around us such as smartphone, MID(Mobile Internet Device), Tablet. These characteristics of information devices services should support soft real-time based time guaranteed multimedia services and control internet appliances. In this situation, soft real-time supported system should be developed to consider as a total aspect of hardware, kernel, middleware, application. But this paper will describe soft real-time supporting and evaluation methods for information device as an aspect of only kernel.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.10
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• pp.977-981
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• 2015

We propose a method for the implementation of an EtherCAT communication bus in a Linux-based open source Computerized Numerical Control (CNC) system. Recently, increasingly more CNC systems support real-time Ethernet protocols such as EtherCAT, which is a high-performance industrial communication protocol. For real-time CNC control over an Ethernet-based protocol, an additional layer driver needs to be implemented between the CNC system and the master of industrial communication protocol. Among the various solutions for the connection layer driver, we employ a Hardware Abstraction Layer (HAL) driver based on Linux. The operation of the implemented CNC system is demonstrated and confirmed by Hal Meter, which is used to observe the pins, signals, or parameters of HAL.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.57-58
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• 2015

실시간성이란 연산의 정확성과 연산 수행시간이 예측 가능한 시간 내에 완료되는 것을 말한다. 범용 운영체제인 리눅스에서는 CFS(Complete Fair Scheduling)을 사용하여 높은 우선순위 태스크에 대한 빠른 응답성을 보장할 수 없기 때문에 실시간성을 제공하지 못한다. 이를 해결하기 위해 RTiK-Linux(Real-Time implanted Kernel for Linux)가 개발되어 리눅스 환경에서 실시간성을 제공하였지만 개발 당시 싱글프로세서 환경만을 고려하여 최근 사용되는 멀티프로세서 환경에서는 실시간성 제공에 어려움이 있다. 본 논문에서는 멀티프로세서 리눅스 상에서 발생하는 RTiK-Linux의 문제점에 대해 설명하고 이에 대한 해결방안을 기술하여 멀티프로세서 리눅스 상에서 실시간성을 제공하기 위한 방안을 연구하였다.

• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.3
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• pp.183-191
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• 2014

The software running on avionic system is required to be highly reliable and productive. The air transport industry has developed ARINC Specification 653(ARINC653) as a standardized software requirement of avionics computers. The document specifies the interface boundary between avionics application software and the core executive software. Dependability in ARINC 653 is provided by spatial and temporal partitioning whilst fault-tolerance is provided by health monitoring mechanism. Legacy real-time operating systems are used to support ARINC653 health monitor on integrated modular avionics(IMA). However, legacy real-time operating systems are costly and difficult to modify the kernel. In this paper, we suggest a Linux-based ARINC653 health monitor. Functionalities to support ARINC653 health monitor are implemented as a Linux kernel module and its performance is evaluated.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.26-32
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• 2022

EtherCAT is an Ethernet-based fieldbus system standardized in IEC 61158 and SEMI, and widely used in the fields of factory automation, semiconductor equipment and robotics. In this paper, an EtherCAT master is implemented on an embedded board with Arm based 64-bit quad-core processor and its jitter performance is evaluated at the output of the network interface to include all the effects of the entire system in the results. For the EtherCAT master system, an open source EtherCAT master stack, Simple Open EtherCAT Master (SOEM), is installed on PREEMPT_RT patched Linux operating system for real-time operation. The results show that the jitter performance is comparable to that of Xenomai-based master and the EtherCAT master with two master instances has similar jitter performance to the EtherCAT master with one master instance.

• The Journal of Information Technology
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• v.4 no.2
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• pp.25-36
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• 2001

In this paper, we present the development of distributed dual real-time kernel system. This paper proposed that real-time applications should be split into small and simple parts with real-time constraints, Following this concept we have designed to preserve the properties of both hard real-time kernel and general kernel. To satisfy these properties, we designed real-time kernel and general kernel, that have their different properties. In real-time tasks, interrupt processing should be un. In general kernel, non real-time tasks or general tasks are run. We compared the results of this study for performance of the proposal real-time kernel with both RT Linux 0.5a and QNX 4.23A, that is, of interrupt latency scheduling precision and message passing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.3
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• pp.547-553
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• 2004

Linux is the one of various RTOS, also embedded linux has being studied with focus on technical stability and commercial utilities. In this paper, the technical trial was discussed on the development of real-time operating system that provides real time capability and extends the network communications ability and would be applied to the maritime mobile communication system through analysis the embedded linux kernel. Some techniques for Analyzing the embedded linux kernel and designing the target board, making the kernel image and porting the kernel are summarized in this paper.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.893-901
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• 2013

This paper suggests a method of developing live media streaming service through Linux server system on android system environment. The android application constructed in the experiment is able to record media while sending it to Linux server. Generated real time media data is send to linux server through Multipart Request class of Apache Tomcat server constructed on Linux system. Also in this research, by utilizing Android video player and media player class, development of android application structures was accomplished, which has methods of; playing live media stream data on video server, or playing live media stream data while saving stream data in cache. The structure and function of suggested system and application is confirmed by series of experiments.