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<Paper uid="C02-1122">
  <Title>Fertilization of Case Frame Dictionary for Robust Japanese Case Analysis</Title>
  <Section position="2" start_page="0" end_page="0" type="intro">
    <SectionTitle>
1 Introduction
</SectionTitle>
    <Paragraph position="0"> To understand a text, it is necessary to find out relations between words in the text. What is required to do so is a case frame dictionary. It describes what kinds of cases each verb has and what kinds of nouns can fill a case slot. Since these relations have millions of combinations, it is difficult to construct a case frame dictionary by hand. We proposed a method to construct a Japanese case frame dictionary automatically by arranging large volumes of parse results by coupling a verb and its closest case component (Kawahara and Kurohashi, 2001).</Paragraph>
    <Paragraph position="1"> This case frame dictionary, however, could not handle complicated expressions: double nominative sentences, non-gapping relation of relative clauses, and case change.</Paragraph>
    <Paragraph position="2"> This paper proposes a method of fertilizing the case frame dictionary to handle these complicated expressions. We take an iterative method which consists of two stages. This means gradual learning of what is understood by an analyzer in each stage. In the first stage, we parse a large raw corpus and construct a Japanese case frame dictionary automatically from the parse results. This is the method proposed by (Kawahara and Kurohashi, 2001). In the second stage, we apply case analysis to the large corpus utilizing the constructed case frame dictionary, and upgrade the case frame dictionary by incorporating newly acquired information. null We conducted a case analysis experiment with the upgraded case frame dictionary, and its evaluation showed effectiveness of the fertilization process.</Paragraph>
  </Section>
class="xml-element"></Paper>