• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.747-748
• /
• 2006

In this paper, we describe photonic sensor interface and driver program based on SOPC(System on a programmable chip) platform. This platform uses device that has ARM922T processor and APEX FPGA area on a chip. As for driver program development, three different methods are tried such as simple firmware, real-time OS based program and embedded Linux based program, and results are compared for SoC implementation.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.04a
• /
• pp.289-291
• /
• 2001

본 논문에서는 실시간처리 리눅스에 기반한 VoIP 단말기를 설계 구현한다. 설계 구현된 하드웨어 시스템은 i386 프로세서를 기반으로 설계되며, 실시간음성처리 지원을 위해 음성코덱 칩과 실시간처리 리눅스인 RTLinux를 사용하여 실시간 음성처리 모듈을 구현한다. 설계 구현된 시스템의 테스트 및 타당성 검증을 위해 LAN환경에서의 음성채팅 프로그램에 적용하여 통화품질을 시험하였다. 음성처리에 사용한 음성처리 모듈은 ITU-T 음성 코덱인 G.723.1 사용하여 30ms 내에 24 바이트로 인코딩/디코딩된 음성 데이타를 전송하도록 구현하였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2013.11a
• /
• pp.48-49
• /
• 2013

복잡한 네트워크 환경에서 광 대역 범위의 보안 정책을 적용하기 위하여 리눅스 커널기반의 Bridge 방화벽을 적용하고 운영시 실시간 트래픽 측정과 모니터링을 위하여 NTOP을 이용하여 실시간 모니터링 시스템을 구현하였다.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.12
• /
• pp.1196-1203
• /
• 2014

Recently, UFRs (Unmanned Flying Robots) have begun to be utilized in various areas for civilian and military applications. Due to this increased utilization, accidents involving UFRsare also increasing. To prevent or monitor accidents caused by UFRs, high-accuracy positioning information is one of the most important technical elements. This paper proposes an efficient UFR monitoring system which provides accurate UFR positioning information with low-cost onboard elements; a small ARM module based on an embedded Linux operating system, a low-cost single frequency GPS receiver with a cheap patch antenna, and a versatile wireless network interface module. The ground monitoring system employs a dual frequency GPS receiver to generate exact UFR coordinates with cm-level accuracy. By processing the UFR measurements based on the Inverse RTK (Real Time Kinematic) method, the ground monitoring system determines the cm-level accurate coordinates of the UFR. The feasibility of the proposed UFR monitoring system was evaluated by three experiments in terms of data loss and accuracy.

• Journal of KIISE:Computing Practices and Letters
• /
• v.8 no.6
• /
• pp.639-646
• /
• 2002

In this paper, we discuss the system configuration and the design issues of CATS-i, a set of installation and administration tools for Linux cluster systems. CATS-i enables users to manage cluster systems easily, quickly, and safety. It integrates many functions, ranging from installing operating systems and applications to real-time monitoring and management of various important resources. In addition, batch job submission and management are included. These functions support a single system image. Finally, a powerful graphic user interface based on Java lets users quickly understand the cluster status and conveniently use the CATS-i on the Web.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.8 no.1
• /
• pp.25-29
• /
• 2013

Recently ARM processor's processing power has been increasing rapidly as it has been applied to consumer electronics products. Because of its computing power and low power consumption, it is used to various embedded systems.( including vision processing systems.) Embedded linux that provides well-made platform and GUI is also a powerful tool for ARM based embedded systems. So short period to develop is one of major advantages to the ARM based embedded system. However, for real-time date processing applications such as an image processing system, ARM needs additional equipments such as FPGA that is suitable to parallel processing applications. In this paper, we developed an embedded system using ARM processor and FPGA. FPGA takes time consuming image preprocessing and numerical algorithms needs floating point arithmetic and user interface are implemented using the ARM processor. Overall processing speed of the system is 60 frames/sec of VGA images.

• The KIPS Transactions:PartA
• /
• v.14A no.5
• /
• pp.295-300
• /
• 2007

The Linux-based embedded systems such as mobile telephones. PDAs and MP3 players are widely in use. USB(Universal Serial Bus) is the interface for data communication between the computers and these peripheral devices. Some embedded systems like intelligent home networking and multimedia streaming require guaranteed QoS(Quality of Service), which is needed for real time transmission of UDP/IP messages through USB. Although USB Ethernet driver is supported by USB Gadget API in Linux, it is unable to provide the desirable QoS required by each type or small embedded systems due to the unpredictability or TCP/IP Stack in Linux. This paper proposes IP-Over-USB to improve QoS of UDP/IP message transmission in the embedded systems using USB in Linux system.

• The KIPS Transactions:PartA
• /
• v.8A no.1
• /
• pp.16-26
• /
• 2001

This paper proposes an extended scheduler model that is an extension of the existing model proposed already in [4, 5], which consists of upper layer task scheduler and lower layer scheduling framework. However, in order to support aperiodic task scheduling, the task scheduler has been divided into two parts, such as periodic task control component and aperiodic task control component. Thus, the proposed model can support various bandwidth-preserving servers that can service aperiodic tasks. The model distinctly separates a classic monolithic kernel scheduler into several kernel components according to their functionality. This enables system developers to implement a new scheduling algorithm or aperiodic task server independent of complex low kernel mechanism, and reconfigure the system at need. In Real-Time Linux [6], we implemented the proposed scheduling framework representative scheduling algorithms, and server bandwidth-preserving servers on purpose to test. Throughout these implementations, we confirmed that a new algorithm or server could be developed independently without updates of complex low kernel modules. In order to verify efficiency of the proposed model, we measured the performance of several aperiodic task servers. The results showed this the performance of model, which even consisted of two hierarchical components and several modules, didnt have such high run-time overhead, and could efficiently support reconfiguration and scheduler development.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.1 no.2
• /
• pp.90-103
• /
• 2006

There are many file systems in various operating systems. Those are usually designed for server environments, where the common cases are usually 'multiple active users', 'great many small files' And they assume a big main memory to be used as buffer cache. So the existing file systems are not suitable for resource hungry embedded systems that process multimedia data streams. In this study, we designed and implemented a new file system which efficiently stores and retrieves multimedia data steams. The proposed file system has a very simple disk layout, which guarantees a quick disk initialization and file system recovery. And we introduced a new indexing-scheme, called the time-based indexing scheme, with the file system. With the indexing scheme, the file system maintains the relation between time and the location for all the multimedia streams. The scheme is useful in searching and playing the compressed multimedia streams by locating exact frame position with given time, resulting in reduction of CPU processing and power consumption. The proposed file system and its APIs utilizing the time-based indexing schemes were implemented firstly on a Linux environment, though it is operating system independent. In the performance evaluation on a real DVR system, which measured the execution time of multi-threaded reading and writing, we found the proposed file system is maximum 38.7% faster than EXT2 file system.

• Journal of Mechanical Science and Technology
• /
• v.17 no.10
• /
• pp.1399-1410
• /
• 2003

In this paper, we develop a joystick manual driving algorithm for an electric vehicle called Cycab. Cycab is developed as a public transportation vehicle, which can be driven either by a manual joystick or an automated driving mode. The vehicle uses six motors for driving four wheels, and front/rear steerings. Cycab utilizes one industrial PC with a real time Linux kernel and four Motorola MPC555 micro controllers, and a CAN network for the communication among the five processors. The developed algorithm consists of two automatic vehicle speed control algorithms for normal and emergency situations that override the driver's joystick command and an open loop torque distribution algorithm for the traction motors. In this study, the algorithm is developed using SynDEx, which is a system level CAD software dedicated to rapid prototyping and optimizing the implementation of real-time embedded applications on distributed architectures. The experimental results verify the usefulness of the two automatic vehicle control algorithms.