• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2B
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• pp.129-137
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• 2003

Multimedia streams, like MPEG continuously retrieve multimedia data because of their incessant playback. While these streams need an efficient support of kernel, the current buffer cache mechanism of Linux kernel such as Unix operating system was designed apt for small files, which is aperiodically requested as well as time uncritical. But, in case of continuous media, the CPU must enormously copy memory from kernel address space to user address space. This must lead to a large CPU overhead. This overhead both degrades system throughput and cannot guarantee QOS. In this paper, we have designed and implemented two memory copy reduction schemes in Linux kernel, direct I/O and one copy. The direct I/O skips the buffer cache layer of Linux kernel and results in dramatic reduction of CPU memory copy overhead. And, the one copy provides a fast disk-to-network data path without copying to user address space. The experimental results show considerable reduction of CPU overhead and throughput improvements.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.542-545
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• 2005

본 연구에서는 Home Network System에서 가전기기들을 제어하고 집안의 상황을 원격지에 있는 사용자에게 전달해 줄 수 있는 Home Network Mobile Robot을 제작하여 보다 더 지능적이고 사용자에게 편리한 Home Network System을 구축한다. 이를 위해 본 논문에서는 실제 Home Network 시스템 하에서의 자율이동 로봇을 고안하였으며 이의 구동을 위해 OS로는 Linux Kernel 2.4를 Porting 하였고, Vision 및 Ethernet 통신이 용이하도록 회로를 설계, 제작하였다.

• 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.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10a
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• pp.635-637
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• 2000

Linux는 다양한 하드웨어 플랫폼을 지원하며, 강력한 네트워크 지원 기능, 다양한 형식의 파일시스템 지원 기능 등 높은 성능을 자랑한다. 그러나, 소스코드의 공개로 인하여 많은 보안상의 취약성을 내포하고 있으며, 최근 이를 이용한 해킹사고가 많이 발생하고 있다. 본 논문에서는 Linux상에 상존하는 보안 취약성을 조사하고, 보안 요구사항을 도출하며, 최근 해킹의 상당부분을 차지하고 있는 Buffer Overflow 공격 방지를 위한 방안으로 커널 수정을 통해 Secure Linux를 개발하고자 한다.

• Journal of IKEEE
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• v.5 no.2 s.9
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• pp.164-173
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• 2001

In this paper, we have designed and implemented a new hard embedded real-time system to satisfy hard real-time constraints in moving independently. Real-time kernel should be small size, fast and predictable. Because of the great variety of demands on real time scheduling, a real time kernel should also include a flexible and re-programmable task scheduling discipline. In this paper, we present that real-time applications should be split into small and simple parts with hard real-time constraints. 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 run. In general kernel, non real time tasks or general tasks are run. The efficiency of the proposed hard embedded real-time system is shown by comparison results for performance of the proposal real time kernel with both RT-Linux and QNX.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.3
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• pp.49-55
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• 2012

Recently, with the rapid development of android-based smartphones, it is becomes a major security issue that the case of Android platform is an open platform. so it is easy to be a target of mobile virus penetration and hacking. Even there are a variety of security mechanisms to prevent the vulnerable points of the Android platform but the reason of most of the security mechanisms were designed at application-level that highly vulnerable to the attacks directly to the operating system or attacks using the disadvantages of an application's. It is necessary that the complementary of the android platform kernel blocks the kernel vulnerability and the application vulnerability. In this paper, we proposed a secure system using linux-based android kernel applied to LIDS(Linux Intrusion Detection and Defense System) and applied a smart phone with s5pc110 chip. As a result, the unauthorized alteration of the application was prevented with a proposed secure system.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.3
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• pp.365-378
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• 2024

The operating system (OS) of mobiles or embedded devices is based on the Linux kernel. These OSs request random numbers from the Linux kernel for system operation, such as encryption keys and security features. To provide random numbers reliably, the Linux kernel has a dedicated random number generator (Linux Pseudo Random Number Generator, LPRNG). Recently, LPRNG has undergone a major structural changes. However, despite the major changes, no security analysis has been published on the structure of the new LPRNG. Therefore, we analyze these structural changes as a preliminary study to utilize the security analysis of the new LPRNG. Furthermore, the differences between before and after the changes are divided into cryptographic and performance perspectives to identify elements that require security analysis. This result will help us understand the new LPRNG and serve as a base for security analysis.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.12
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• pp.618-629
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• 2007

In this paper, we propose an effective memory test environment, called a virtualized kernel, for 64bit multi-core computing environments. The term of effectiveness means that we can test all of the physical memory space, even the memory space occupied by the kernel itself, without rebooting. To obtain this capability, our virtualized kernel provides four mechanisms. The first is direct accessing to physical memory both in kernel and user mode, which allows applying various test patterns to any place of physical memory. The second is making kernel virtualized so that we can run two or more kernel image at the different location of physical memory. The third is isolating memory space used by different instances of virtualized kernel. The final is kernel hibernation, which enables the context switch between kernels. We have implemented the proposed virtualized kernel by modifying the latest Linux kernel 2.6.18 running on Intel Xeon system that has two 64bit dual-core CPUs with hyper-threading technology and 2GB main memory. Experimental results have shown that the two instances of virtualized kernel run at the different location of physical memory and the kernel hibernation works well as we have designed. As the results, the every place of physical memory can be tested without rebooting.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.17-18
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• 2011

최근 빠른 응답성과 정확성을 요구하는 임베디드 시스템의 사용이 증가됨에 따라 임베디드 시스템의 시간 정확성을 만족 시키는 경성 실시간성의 중요성이 커지고 있다. 이러한 임베디드 시스템의 운영체제로는 응용프로그램 개발의 편의성을 위해 범용 운영체제인 Linux를 많이 사용하며, Linux에 실시간성 제공을 위해 RT-Linux(Real Time - Linux)를 사용하고 있다. RT-Linux의 경우 경성 실시간성을 제공하지만 어셈블러를 사용해야 하므로 개발자가 다루기 힘들다는 단점이 존재한다. 이에 따라 Linux에 경성 실시간성을 제공하고 개발자에게 개발의 편의성을 제공하는 방법에 대한 연구가 필요하다. 본 논문에서는 범용운영체제인 Linux에 경성 실시간성을 제공하기 위해 x86기반의 Window에 실시간성을 제공하는 RTiK(Real-Time implanted Kernel)을 Linux에 모듈 형태로 적재하여 실시간성을 제공할 수 있는 방법을 설계 및 구현하였다.