• Journal of KIISE:Software and Applications
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• v.31 no.8
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• pp.1083-1091
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• 2004

This paper presents a chunking system employed as a preprocessing module to the parser in a Chinese to Korean machine translation system. The parser can benefit from the dependency information provided by the chunking module. The chunking system was implemented using transformation-based learning technique and an effective interface that conveys the dependency information to the parser was also devised. The module was integrated into the machine translation system and experiments were performed with corpuses collected from Chinese websites. The experimental results show the introduction of chunking module provides noticeable improvements in the parser's performance.

• The KIPS Transactions:PartB
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• v.15B no.1
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• pp.69-72
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• 2008

This study aims to identify dependency structures in Korean sentences with the cascaded chunking. In the first stage of the cascade, we find chunks of NP and guess grammatical relations (GRs) using Support Vector Machine (SVM) classifiers for all possible modifier-head pairs of chunks in terms of GR categories as subject, object, complement, adverbial, etc. In the next stages, we filter out incorrect modifier-head relations in each cascade for its corresponding GR using the SVM classifiers and the characteristics of the Korean language such as distance between relations, no-crossing and case property. Through an experiment with a parsed and GR tagged corpus for training the proposed parser, we achieved an overall accuracy of 85.7%.

• Journal of the Korea Society for Simulation
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• v.19 no.1
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• pp.103-111
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• 2010

Syntactic analysis is an important step in natural language processing. However, we cannot use the syntactic analyzer in Korean for low performance and without robustness. We propose new robust, high speed and high performance Korean syntactic analyzer using CRFs. We treat a parsing problem as a labeling problem. We use a cascaded chunking for Korean parsing. We label syntactic information to each Eojeol at each step using CRFs. CRFs use part-of-speech tag and Eojeol syntactic tag features. Our experimental results using 10-fold cross validation show significant improvement in the robustness, speed and performance of long Korea sentences.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.10
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• pp.2718-2731
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• 2023

This paper presents a method of using syntax and shallow semantic analysis for Vietnamese question generation (QG). Specifically, our proposed technique concentrates on investigating both the syntactic and shallow semantic structure of each sentence. The main goal of our method is to generate questions from a single sentence. These generated questions are known as factoid questions which require short, fact-based answers. In general, syntax-based analysis is one of the most popular approaches within the QG field, but it requires linguistic expert knowledge as well as a deep understanding of syntax rules in the Vietnamese language. It is thus considered a high-cost and inefficient solution due to the requirement of significant human effort to achieve qualified syntax rules. To deal with this problem, we collected the syntax rules in Vietnamese from a Vietnamese language textbook. Moreover, we also used different natural language processing (NLP) techniques to analyze Vietnamese shallow syntax and semantics for the QG task. These techniques include: sentence segmentation, word segmentation, part of speech, chunking, dependency parsing, and named entity recognition. We used human evaluation to assess the credibility of our model, which means we manually generated questions from the corpus, and then compared them with the generated questions. The empirical evidence demonstrates that our proposed technique has significant performance, in which the generated questions are very similar to those which are created by humans.

• The KIPS Transactions:PartB
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• v.9B no.6
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• pp.791-798
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• 2002

In this thesis. we present a new method for inducing a probabilistic dependency grammar (PDG) from text corpus. As words in Korean are composed of a set of more basic morphemes, there exist various dependency relations in a word. So, if the induction process does not take into account of these in-word dependency relations, the accuracy of the resulting grammar nay be poor. In comparison with previous PDG induction methods. the main difference of the proposed method lies in the fact that the method takes into account in-word dependency relations as well as inter-word dependency relations. To access the performance of the proposed method, we conducted an experiment using a manually-tagged corpus of 25,000 sentences which is complied by Korean Advanced Institute of Science and Technology (KAIST). The grammar induction produced 2,349 dependency rules. The parser with these dependency rules shoved 69.77% accuracy in terms of the number of correct dependency relations relative to the total number dependency relations for best-1 parse trees of sample sentences. The result shows that taking into account in-word dependency relations in the course of grammar induction results in a more accurate dependency grammar.

• Korean Journal of Cognitive Science
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• v.20 no.4
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• pp.507-533
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• 2009

This paper examines the time course and processing patterns of filler-gap dependencies in Korean relative clauses, using an eyetracking method. Participants listened to a short story while viewing four pictures of entities mentioned in the story. Each story is followed by an auditorily presented question involving a relative clause (subject relative or dative relative). Participants' eye movements in response to the question were recorded. Results showed that the proportion of looks to the picture corresponding to a filler noun significantly increased at the relative verb affixed with a relativizer, and was largest at the filler where the fixation duration on the filler picture significantly increased. These results suggest that online resolution of the filler-gap dependency only starts at the relative verb marked with a relativiser and is finally completed at the filler position. Accordingly, they partly support the filler-driven parsing strategy for Korean, as for head-initial languages. In addition, the different patterns of eye movements between subject relatives and dative relatives indicate the role of case markers in parsing Korean sentences.

• Journal of KIISE:Software and Applications
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• v.33 no.5
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• pp.470-480
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• 2006

The longer the input sentences, the worse the parsing results. To improve the parsing performance, many methods about long sentence segmentation have been reserarched. As an isolating language, Chinese sentence has fewer cues for sentence segmentation. However, the average frequency of comma usage in Chinese is higher than that of other languages. The syntactic information that the comma conveys can play an important role in long sentence segmentation of Chinese languages. This paper proposes a method for classifying commas in Chinese sentences according to the context where the comma occurs. Then, sentences are segmented using the classification result. The experimental results show that the accuracy of the comma classification reaches 87.1%, and with our segmentation model, the dependency parsing accuracy of our parser is improved by 5.6%.

• The KIPS Transactions:PartB
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• v.14B no.2
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• pp.141-144
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• 2007

The longer the input sentences, the worse the syntactic parsing results, Therefore, a long sentence is first divided into several clauses and syntactic analysis for each clause is performed. Finally, all the analysis results art merged into one, In the merging process, it is difficult to determine the dependency among clauses, To handle such syntactic ambiguity among clauses, this paper proposes an SVM-based clause-dependency determination method. We extract various features from clauses, and analyze the effect of each feature on the performance. We also compare the performance of our proposed method with those of previous methods.

• Annual Conference on Human and Language Technology
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• 2014.10a
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• pp.78-80
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• 2014

본 논문에서는 한국어 구문 분석을 위해 3차 의존 파싱 방법을 적용한 성능 결과를 제시한다. 3차 의존 파싱에서는 조부모 (grandparent) 노드 정보까지 참조함으로써 2차 자질의 한계를 넘어 보다 복잡하고 다양한 자질을 고려할 수 있다. 실험 결과 3차 의존 파싱은 기존의 2차 한국어 의존 파싱의 성능을 향상시켰다.

• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.327-329
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• 2000

기존의 구문분석 방법은 구구조문법과 의존문법에 기반한 것이 대부분이다. 이러한 구문분석은 다양한 분석 결과들이 분석되는 동안 많은 시간이 소요되며, 잘못된 분석 결과를 찾아 내어 삭제하기(pruning)도 어렵다. 본 논문은 구문분석에 필요한 의존문법을 적용하기 이전에, 단위화(Chunking) 방법을 사용하는 것을 제안한다. 이렇게 함으로써, 의존문법에 적용하는 차트의 수를 줄이게 되고, 의존관계의 설정 범위(scope)도 제한을 가할 수 있으며, 구문분석 속도 또한 빨라지게 된다.