• Title/Summary/Keyword: LR 파싱

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An Efficient Incremental Parsing for LR Parsers (LR 파서를 위한 효율적인 점진적 파싱)

  • An, Hui-Hak
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.6
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    • pp.1660-1669
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    • 1998
  • 본 논문에서는 실제 사용에 있어서 시간과 기억 장소를 상당히 요구하는 기존의 점진적 파싱 알고리즘들을 조사하여, 이들보다 효율적인 점진적 LR 파싱 알고리즘을 제안한다. 문법 기호를 포함하는 확장형 LR 파싱표를 본 논문에서 제안한 점진적 LR 파싱 알고리즘을 적용한다. 여러 문장의 경우에 본 점진적 LR 파싱 알고리즘을 이용하여 파싱 단계와 기억 장소를 감소시켰다. 본 알고리즘은 복잡하고 큰 문법의 경우에 더욱 효과적이다.

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On Design and Implementation of Incremental LR Parsing Algorithm Using Changed Threed Tree (변화된 스레드 트리를 이용한 점진적 LR 파싱 알고리즘 구현 및 설계)

  • Lee, Dae-Sik
    • Convergence Security Journal
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    • v.5 no.4
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    • pp.19-25
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    • 2005
  • Threaded Tree is the data structure that can express parse stack as well as parse tree with LR parsing table. $Larchev\^{e}que$ makes Threaded Tree and Incremental Parsing with stack. This paper suggests the algorithm consisting of changed threaded tree without stack in order to reduce reparsing node and parsing speed. Also, it suggests incremental parsing algorithm to get rid of the reparsing process in node.

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Application of Single-State Parsing Automata to LR Grammars (LR 문법에 대한 단일상태파싱오토마톤의 적용)

  • Lee, Gyung-Ok
    • Journal of KIISE
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    • v.43 no.10
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    • pp.1079-1084
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    • 2016
  • Single-state parsing automata have a characteristic such that the decision of an action depends only on the current state but not on the parsing history. The memory space and the parsing time of single-state parsing automata are less than the memory space and the parsing time of LR automata. However, the applicable grammar class of single-state parsing automata is less than that of LR automata. This paper provides extended single-state parsing automata, which are applicable to LR grammars. In the prior work, the special state, referred to as the cyclic state was not treated in the construction of single-state parsing automata, and hence, the applicable grammar class was less than LR grammars. The paper solves the problem of cyclic states by processing dynamic information depending on an input string. The proposed method expands the application of grammar class of single-state parsing automata to LR grammars.

Generalized LR Parser with Conditional Action Model(CAM) using Surface Phrasal Types (표층 구문 타입을 사용한 조건부 연산 모델의 일반화 LR 파서)

  • 곽용재;박소영;황영숙;정후중;이상주;임해창
    • Journal of KIISE:Software and Applications
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    • v.30 no.1_2
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    • pp.81-92
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    • 2003
  • Generalized LR parsing is one of the enhanced LR parsing methods so that it overcome the limit of one-way linear stack of the traditional LR parser using graph-structured stack, and it has been playing an important role of a firm starting point to generate other variations for NL parsing equipped with various mechanisms. In this paper, we propose a conditional Action Model that can solve the problems of conventional probabilistic GLR methods. Previous probabilistic GLR parsers have used relatively limited contextual information for disambiguation due to the high complexity of internal GLR stack. Our proposed model uses Surface Phrasal Types representing the structural characteristics of the parse for its additional contextual information, so that more specified structural preferences can be reflected into the parser. Experimental results show that our GLR parser with the proposed Conditional Action Model outperforms the previous methods by about 6-7% without any lexical information, and our model can utilize the rich stack information for syntactic disambiguation of probabilistic LR parser.

Constructing a of Single State Parsing Automaton (단일 상태 파싱 오토마톤의 생성)

  • Lee, Gyung-Ok
    • Journal of KIISE:Software and Applications
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    • v.35 no.11
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    • pp.701-704
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    • 2008
  • A general automaton allows multiple input transitions, so a special treatment is required when the history of transitions is needed. An LR automaton keeps the past transitions in the stack to use them during parsing. On the other hand, when each state in an automaton contains in itself the past transition history, the trace overhead of past transitions is unnecessary. The paper suggests a single state parsing automaton that does not depend on the past transitions. The applicable grammar class is less than LR grammars, but each state in a new automaton contains the past information, so the tracing of the history is not required compared to LR automaton.

Extended LR Methods for Efficient Parsing with Feature-based Grammars

  • Le, Kang-Hyuk
    • Korean Journal of Cognitive Science
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    • v.15 no.1
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    • pp.25-33
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    • 2004
  • This paper discusses two problems with LR parsing with regard to constructing parsing tables with feature-based grammars. First, we show that traditional LR parsing methods suffer from nontermination and nondeterminism problems when they are applied to feature-based grammars. We then present an LR method for feature-based grammars that avoids both nontermination and nondetermisim by making use of partial information of a feature structure. Second, we describe the problem of adapting LR parsing to feature-based grammars with schematic rules (i.e., rules that do not contain enough information to construct parsing tables). To remedy this problem, we propose a rule inference algorithm which instantiates underspecified rules into more specified ones containing enough information.

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A LR Parsing Algorithm for Tree Adjoining Grammar (트리 접합 문법의 LR파싱 알고리즘)

  • 한성국
    • Korean Journal of Cognitive Science
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    • v.6 no.3
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    • pp.41-63
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    • 1995
  • We present a LR,bottom-up parsing algorithms for TAG. We will introduce the adjoining rules system to handle the formal properties of TAG and to describe the parsing process more effectively. We will consider the context-free behavior of TAG at the adjoining instant. Then we will present the LR bottom up parsing algorithm for TAG by using this property. The basic idea behind a LR bottom up parsing algorithm can be applied to parsing TAG with other conventional algorithms.

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Shift-first Strategy for Resolving Conflicts in the LR Parsing (LR 파싱에서 충돌 해결을 위한 Shift 우선 전략)

  • Lee, Yong-Seok;Hwang, Yi-Gyu
    • Annual Conference on Human and Language Technology
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    • 1996.10a
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    • pp.484-488
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    • 1996
  • LR 파싱은 프로그래밍 언어를 위한 빠른 파싱 방법을 제공한다. 그러나 이 방법의 단점은 자연어와 같은 다양한 모호성을 가지는 문법에 적합하지 못하다. 모호성을 가지는 문법은 파싱 테이블 상에서 충돌을 야기하게 되는데 이를 해결하는 방법에 대한 연구가 많이 있어 왔다. 문장이 길어질 경우 구문 분석 도중 이러한 모호성이 파싱 효율에 큰 영향을 미치게 되는데, 본 논문에서는 Shift 우선 전략으로 LR 파싱의 효율적인 특징을 유지하면서 이러한 충돌을 해결할 수 있음을 보인다.

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Grammar Classes Generating Single State Parsing Automata (단일 상태 파싱 오토마톤을 생성하는 문법 클래스들)

  • Lee, Gyung-Ok
    • Journal of KIISE:Software and Applications
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    • v.41 no.7
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    • pp.518-522
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    • 2014
  • A single state parsing automaton has the characteristics of the decision of actions which do not depend on the history of the parsing paths but on the current state. The single state parsing automaton hence has the advantage of the reduced parsing time and a small memory requirement compared to those of the conventional LR automaton. However, currently, the grammar classes generating single state parsing automata have not been known. This paper deals with the grammar classes generating single state parsing automata; in addition, this paper gives the generating method of single state parsing automata of the grammar classes.