• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.625-627
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• 2004

최근 들어 인터넷의 발달과 더불어 PDA, 핸드폰과 같은 모바일 디바이스와 다양한 정보가전용 기기들에 네트워크 기반의 자바기술이 적용되고 있으며, 이러한 자바 기술을 사용함으로써 플랫폼 독립성 이식성, 보안성, 이동성 둥의 장점을 얻을 수 있다. 그러나, 자바로 작성된 응용프로그램은 C, C++로 작성된 응용프로그램 보다 수행속도가 느리다는 단점이 있다. 이러한 문제점을 해결하기 위해서는 자바가상머신의 성능향상이 필수적이다. 지금까지 메모리 관리를 위한 가비지 컬렉션, 소프트웨어나 하드웨어를 이용한 바이트 코드 변환, 인라인캐시(inline-cache)를 사용한 접근 속도 향상 등 많은 부분에서 활발한 연구가 진행되고 있다. 본 논문에서는 모바일 플랫폼에서 동작하는 KVM(kilo-virtual machine)의 성능향상을 위한 쓰레드 구조를 분석하고 설계한다.

• Journal of Satellite, Information and Communications
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• v.12 no.3
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• pp.108-113
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• 2017

The OBCP called 'operator on board' is that of a procedure to be executed on-board, which can be easily be loaded, executed, and also replaced, without modifying the remainder of the FSW. The use of OBCP enhances the on-board autonomy capabilities and increases the robustness to ground stations outages. The OBCP engine which is the core module of OBCP component in the FSW interprets and executes of the procedures based on script language written using a high-level language, possibly compiled, and it is relying on a virtual machine of the OBCP engine. FSW team in KARI has studied OBCP since 2010 as FSW team's internal projects, and made some OBCP engines such as Java KVM, RTCS/C and KKOMA on ERC32 processor target only for study. Recently we have been studying ESA's OBCP standard and implementing Lua and MicroPython on LEON2-FT/AT697F processor target as the OBCP engine. This paper presents the design and implementation of Lua for the OBCP engine on AT697F processor with VxWorks RTOS, and describes the evaluation result and performance of the OBCP engine.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.199-201
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• 2015

국방 분야에서 전술작전센터를 구성하는 전술작전통제 플랫폼은 다양한 내/외부 체계 시험 장치를 연동하여 교전/작전 통제를 수행하는 플랫폼이다. 기존의 전술작전통제 플랫폼은 서로 다른 환경에서 개발된 시험 장치 소프트웨어를 통합 구축하는데 어려움이 있으며, 플랫폼을 구성하는 서버 자원의 탄력적 분배가 불가능하다. 본 연구는 전술작전센터를 구성하는 전술작전통제 플랫폼을 오픈스택 클라우드 및 KVM 하이퍼바이저를 기반으로 구축하여 내/외부 체계 시험 장치 소프트웨어의 실행 환경을 가상 머신으로 제공하였으며, 가상 머신 간 고속 데이터 통신을 위해 데이터 분산 서비스 및 10Gbps 이더넷, QDR 인피니밴드 네트워크를 활용하였다. 또한 오픈스택 클라우드 기반 전술작전통제 플랫폼의 네트워크를 구성하는 10Gbps 이더넷 및 QDR 인피니밴드 네트워크상에서 데이터 분산 서비스의 성능 평가를 수행하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.2
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• pp.115-121
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• 2014

Since the rapid development of information age and information technology might be considered to cause environmental problems, Green IT is perceived as core technology for low carbon green growth and the minimum waste of electricity. In this vein, Green IT is becoming new paradigm of focusing on natural environment. This study examines current various IT required for green growth, and studies various methods for diminution of carbon discharge in Korea and other countries. Especially, it focuses on the diminution effect of carbon discharge by using Green PC, and compares the difference of voltage, voltaic current, and the use of electricity between Normal PC and Green PC by using HPM-300A, and measures carbon discharge of Normal PC and Green PC. The result shows that the diminution effect of $CO_2$ discharge of Green PC is amount to 11.5Kg per year, and the effect of green growth is up to the conservation of 2 or 3 pine trees.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.11
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• pp.5642-5670
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• 2017

Antivirus is an important issue to the security of virtual machine (VM). According to where the antivirus system resides, the existing approaches can be categorized into three classes: internal approach, external approach and hybrid approach. However, for the internal approach, it is susceptible to attacks and may cause antivirus storm and rollback vulnerability problems. On the other hand, for the external approach, the antivirus systems built upon virtual machine introspection (VMI) technology cannot find and prohibit viruses promptly. Although the hybrid approach performs virus scanning out of the virtual machine, it is still vulnerable to attacks since it completely depends on the agent and hooks to deliver events in the guest operating system. To solve the aforementioned problems, based on in-memory signature scanning, we propose an agentless runtime antivirus system VirtAV, which scans each piece of binary codes to execute in guest VMs on the VMM side to detect and prevent viruses. As an external approach, VirtAV does not rely on any hooks or agents in the guest OS, and exposes no attack surface to the outside world, so it guarantees the security of itself to the greatest extent. In addition, it solves the antivirus storm problem and the rollback vulnerability problem in virtualization environment. We implemented a prototype based on Qemu/KVM hypervisor and ClamAV antivirus engine. Experimental results demonstrate that VirtAV is able to detect both user-level and kernel-level virus programs inside Windows and Linux guest, no matter whether they are packed or not. From the performance aspect, the overhead of VirtAV on guest performance is acceptable. Especially, VirtAV has little impact on the performance of common desktop applications, such as video playing, web browsing and Microsoft Office series.