• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.217-219
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• 2006

내장형 시스템에서 많이 채택되고 있는 자바 가상 머신의 성능을 향상시키기 위해 interpreter. just-in-time 컴파일러 (JITC), ahead-of-time 컴파일러 (AOTC) 세가지 방식을 모두 지원하는 자바 가상 머신을 설계하고 구현하였다. 특히 이런 환경을 지원하기 위한 효율적인 JITC와 시스템의 idle 시간에 JITC모듈을 활용하기 위한 client-AOTC의 설계와 구현에 대해 살펴보고 현재까지의 실험 결과를 보고한다.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.8
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• pp.868-872
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• 2010

Many embedded Java systems are equipped with limited memory, which can constrain the code cache size provided for Java just-in-time compilation, affecting the Java performance. This paper proposes expanding the limited code cache when it is full, by saving the machine code for some methods in the code cache into the file system of the permanent storage and reloading it to the code cache when they are re-invoked later. This is applying the client ahead-of-time compilation during the execution time for the purpose of enlarging the code cache. Our experimental results indicate that the proposed execution method can improve the performance by as much as 1.6 times compared to the conventional method, when the code cache size is reduced by half.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06c
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• pp.540-544
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• 2010

모바일 환경에서 웹 브라우저 활용이 늘어나고 웹 페이지를 통한 다양한 서비스가 제공되면서 브라우저에서의 자바스크립트 성능이 중요한 요소가 되었다. 자바스크립트 엔진의 성능 개선을 위해 기존에 사용하던 인터프리터 대신에 머신 코드를 실행 시간에 생성하는 적시 컴파일러(JITC)가 도입되었다. 특히 모바일 환경에서 WebKit의 자바스크립트 엔진인 SquirrelFish Extreme(SFX)이 많이 사용되고 있다. 본 논문에서는 SFX의 성능 향상을 위하여 적시 컴파일러를 통해 생성된 머신 코드를 파일 시스템을 활용하여 파일에 저장하였다가 재사용하는 클라이언트 AOTC(ahead-of-time compilation) 방식을 제시하고 초기 실험 결과를 제시한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11B
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• pp.1715-1724
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• 2010

This paper analyzes the limitations and provides alternative options for Korean Military LISI model, which is based on interoperability assessment model, LISI(Level of Information System Interoperability), developed for US defense information systems and reformed to suit the Korean Military environment by ADD. Korean Military's LIST model is applied to all systems(information system, weapon systems, non-weapon systems)' interoperability assessment defined in acquisition regulations by Joint Interoperability Test Center, a subordinate unit of Defense Command and Control Forces and the only assessment agency of defense interoperability. LISI was basically developed as an assessment model for information system's interoperability, but due to it's shortfall in assessing complex systems including information systems, weapon and non-weapon systems required from New environment SOSI(System of Systems Interoperability) has recently been researched and developed. On the other hand, it is inevitable that Korean Military's LISI model face fundamental limitations as an interoperability assessment tool for Defense Information System as well as for weapon and non-weapon systems, since it was benchmarked and reformed from the US LISI model. In order to overcome such limitations, MND and associated agencies are providing improvement methods through studies. This paper will provide LISI capability model's assessment criteria on Application(P), Infrastructure(I), Data(D), restraints of on comparison assessment process of unit systems evaluated and politic alternatives to overcome the restraints.