• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.913-916
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• 2006

의료시스템은 모든 것이 병원 네트워크를 중심으로 의료 서비스가 제공되어 진다. 하지만 자연재해, 천재지변과 같은 갑작스런 환자 발생으로 인한 응급 이동 사항, 혹은 진료자의 외진 및 환자 방문시에는 일반 데스크탑 PC에서 이루어지는 상태의 의료 서비스가 아닌 휴대하기 간편하고 언제 어디서나 의료서비스를 받을 수 있는 Personal Digital Assistant (PDA)와 같은 휴대용 기기에서의 의료시스템이 필요하다. PDA는 휴대가 용이하며 유선 네트워크 시스템에 구애받지 않는 무선 모바일 장비로서 무선 통신이 가능한 곳이라면 언제 어디서라도 환자에 대한 의료 정보를 조회할 수 있다. 또한 PDA의 통신 기술로서 병원과의 실시간 통신이 가능하여 응급 환자에 대해 빠른 진료를 제공 할 수 있다. 이와 더불어 임베디드기기 프로세서의 발달로 인하여 연산처리 기술도 많은 향상을 가져왔고 이로 인하여 기존의 PDA에서의 문제였던 DICOM영상의 조회 및 처리속도에도 많은 향상을 가져왔다. 이에 본 연구에서는 의료영상 표준인 DICOM표준을 따르며 이동성이라는 장점을 통하여 언제 어디서나 손쉽게 진료자가 환자의 의료정보 및 의료 영상을 조회할 수 있도록 하는 PDA용 모바일 의료영상 조회 시스템을 PXA255 기반의 Embedded Linux 상에서 QT/C++을 사용하여 구현하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.12
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• pp.1196-1203
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• 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
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• v.13 no.2
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• pp.75-85
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• 2007

There are many embedded systems which store and play multimedia streams on optical media such as recordable cd and dvd. Some of those are PVRs, DVRs, and camcorders. In this paper we describe the design and implementation of a new, well structured, fully documented, operating system independent and open source optical media API which can be used in various applications and embedded systems. We also design an ISO-9660 compliant optical media layout, an API set and the scenario for real-time recording. To prove the usability, we develop a text application to replace well-known CD-burning software, cdrecord, and a graphic burning application. All the implementations are firstly done on Linux PC environment, and then ported to a commercial embedded system which uses pSOS as an operating system.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.6
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• pp.637-647
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• 2010

Recent embedded systems are being more complicated due to their hierarchical software architecture including operating systems. The performance of such complicated software architecture could not be well analyzed through separate analysis of each software layer; the combined effect and the interactions among the whole software layers should be considered. In this paper, we show the design and implementation of a performance analysis framework that enables hierarchical analysis of performance of Linux-based embedded systems considering interactions among the software layers. By using the proposed framework, we can obtain useful run-time information about a hierarchical software structure which usually consists of user-defined function layer, library function layer, system call layer, and kernel events layer. Experimental results reveal that the proposed framework could accurately identify the performance bottlenecks with the corresponding software layers during executions of target applications through the accompanying sub-steps of the analysis: the actual execution paths, the execution time of each observed event in each software layer, and the control flows across the software layers.

• The KIPS Transactions:PartD
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• v.16D no.3
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• pp.441-450
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• 2009

This paper describes the design and implementation of Personal Mobile Broadcasting Service which bases on embedded Linux and it supports personal broadcasting in wireless network environments. Recently, with the advent of various wireless networks and the increased use of high performance mobile devices, the demand for personal mobile broadcasting is being increased. The personal mobile broadcasting service makes it possible that mobile users create contents using their own mobile devices while they are moving or they are in any place. And then, it sends the created contents to server in real-time where their blogs are. Users connected to the content creator's blog can play the contents in real-time. With the implemented personal mobile broadcasting service, mobile users can share multimedia contents in real-time through wireless networks. And, it also helps users to construct their own broadcasting stations where they can broadcast the scene of the accident or public performance in real-time.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.413-416
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• 2004

The tracking antenna system must be always pointed to a satellite for data link among moving vehicles. Especially, for an antenna mounted on a moving vehicle, it needs the stabilized the antenna system. So, software and hardware, signal processing of motion detection sensors, real-time processing of vehicle dynamics, trajectory estimation of satellite, antenna servo mechanism, and tracking algorithm, are unified in the antenna system. The purpose of this paper is to design the embedded tracking antenna control system for satellite communication. The embedded OS(Operating System) based stabilization and tracking algorithm was implemented. The performance of the designed embedded control system was verified by the real satellite communication test.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.6
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• pp.630-638
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• 2002

Debugging for application Programs running in embedded Linux systems has mostly been done remotely due to the limited resources of the target systems. The gdb, which is one of the most famous debugger in Linux systems, does not support the debugging of the child processes which is created by the fork system call in local and remote environments. Therefore, by using gdb, developers can debug the application programs that have single-process structure in local and remote environments, but they cannot debug the application programs that have multi-process structures by using gdb in remote environments. Also, although developers can debug the application programs that have multi-process structures by using gdb in local environments, it needs additional and unnecessary codings. In this paper, we presents the remote debugging scheme that can be used for debugging multi-process structured applications. The proposed scheme is implemented by using the library wrapping scheme, and also uses the conventional system components such as gdb and gdbserver.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.6
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• pp.48-56
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• 2008

This study provides to car driver with car exhaust gas and sensor information which are car trouble code in engine and many sensors when the car has some problems. This is to provide car manager with many information of car sensors when we go to vehicle maintenance. For example, information of engine RPM, fuel system, intake air temperature, air flow sensors and oxygen sensors can provide to owner or garage, and also add to multimedia system for mp3 files and video files. This system consists of embedded linux system of low power while driving the car which uses OBD-II protocols and zigbee communication interface from CAN communication of car system to self-diagnosis embedded system of car. Finally, low power embedded system has a lot of application and OBD-II protocols for embedded linux system and CAN communication which get sensor informations of car control sensor system while driving the car.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.7
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• pp.413-420
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• 2006

The speed of present-day network technology exceeds a gigabit and is developing rapidly. When using TCP/IP in these high-speed networks, a high load is incurred in processing TCP/IP protocol in a host CPU. To solve this problem, research has been carried out into TCP/IP Offload Engine (TOE). The TOE processes TCP/IP on a network adapter instead of using a host CPU; this reduces the processing burden on the host CPU. In this paper, we developed two software-based TOEs. One is the TOE implementation using an embedded Linux. The other is the TOE implementation using Lightweight TCP/IP (lwIP). The TOE using an embedded Linux did not have the bandwidth more than 62Mbps. To overcome the poor performance of the TOE using an embedded Linux, we ported the lwIP to the embedded system and enhanced the lwIP for the high performance. We eliminated the memory copy overhead of the lwIP. We added a delayed ACK and a TCP Segmentation Offload (TSO) features to the lwIP and modified the default parameters of the lwIP for large data transfer. With the aid of these modifications, the TOE using the modified lwIP shows a bandwidth of 194 Mbps.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.371-372
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• 2017

최근 IoT 디바이스가 증가함에 따라 IoT 환경에서 사용되고 있는 임베디드 시스템에 대한 보안의 중요성이 대두되고 있다. SELinux는 Linux 의 보안성을 강화시키는 보안 강화 커널로, 시스템의 취약점을 이용한 공격을 방지할 수 있는 Linux 시스템 보안의 핵심적인 요소이다. 본 논문에서는 임베디드 리눅스 빌드 시스템중 가장 활발히 진행되고 있는 Yocto 프로젝트를 활용하여 임베디드 리눅스 시스템에 SELinux를 적용하는 방법을 연구하고자 한다.