Journal of KIISE:Software and Applications (한국정보과학회논문지:소프트웨어및응용)

Korean Institute of Information Scientists and Engineers (한국정보과학회)
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Performance Evaluation of Left-Comer and Look-Ahead Chart Parsing for Small-Sized Context Free Grammar

소규모 문맥 자유 문법에 대한 Left-Corner / Look-Ahead 차트 파싱 알고리즘의 성능 평가

  • Published : 2009.07.15
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Abstract

A left-comer and look-ahead chart parsing algorithm suppresses the generation of meaningless intermediate structures, and thus, gains parsing speed-ups. However, the algorithm requires additional costs to maintain left-comer and look-ahead information throughout the parsing process. Albeit the additional costs, previous research shows that significant parsing speed-ups have been achieved for large-sized context-free grammars. In this paper, we perform similar experiments with a small-sized grammar. We still get parsing speed-ups, but relatively low. We also find that left-comer information has rather negative effects on parsing speed-ups.

차트 파싱 알고리즘에서 left-corner와 look-ahead 정보를 이용하여 불필요한 중간 구조가 생성되지 않도록 함으로써 파싱 속도를 향상시키는 방법이 제안된 바 있다. left-corner와 look-ahead 정보를 이용할 경우 불필요한 중간 구조가 생성되지 않으므로 파싱 속도가 빨라지겠지만 이러한 정보를 유지 관리하고 참조하는 데 따른 추가 비용이 발생한다. 이러한 추가 비용이 발생함에도 불구하고 대규모 문법을 사용하여 파싱을 할 때에는 파싱 속도가 상당한 많이 향상되었다는 연구 결과가 있었다. 본 논문에서 는 소규모 문법을 사용했을 때 파싱 속도가 어느 정도 향상되는가를 관찰하는 실험을 하였다. 실험 결과 소규모의 문법에서는 파싱 속도 향상 정도가 상대적으로 낮았으며 left-corner 정보는 파싱 속도를 향상 시키는 것이 아니라 오히려 저해한다는 사실을 알 수 있었다.

Keywords

References

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