<?xml version="1.0" standalone="yes"?>
<Paper uid="C86-1147">
  <Title>Translation by Understanding: A Machine Translation Sy,i;tem LUTE Hirosato NOMURA, Shozo NAITO, Yasuhiro KATAGIRI, and Aldra SHIMAZU</Title>
  <Section position="3" start_page="0" end_page="6271" type="intro">
    <SectionTitle>
2. Language Understanding Model
</SectionTitle>
    <Paragraph position="0"/>
    <Section position="1" start_page="0" end_page="0" type="sub_section">
      <SectionTitle>
2.1 Memory Organization
</SectionTitle>
      <Paragraph position="0"> Knowledge can be organized into various memory structures depending on the type of knowledge. TheMe structures are usually hierarchical and consist of three layers; 1) long-term memory, 2) discourse memory, and 3) episodic memory (or short-term memory).</Paragraph>
      <Paragraph position="1"> Long-term memory stores knowledge such as dictionaries, grammars, experiences, cmnmon-sense knowledge, expert knowledge, and procedural knowledge such as how to infm&amp;quot; a fact from a collection of facts. Knowledge also contains recta-level knowledge such as knowledge about the characteristics of knowledge and the nsage of it.</Paragraph>
      <Paragraph position="2"> Discourse memory stores knowledge concerning the situation as an environment of utterances, and the history of understandings such as &amp;quot;Who is the author?&amp;quot;, &amp;quot;What is the topic?&amp;quot;, and &amp;quot;What is the purpose of the discourse segment?&amp;quot;, Episodic memory steres the meaning structure of the ongoing segment of the text and its construction is the main issue in the discussion of sentence analysis.</Paragraph>
      <Paragraph position="3"> The memory model described above can be applied to account for a number of linguistic phenomena. For example, the difference between two Japanese anaphoric expressions &amp;quot;sono ( 7C/ ~),, and &amp;quot;ano ( ~ C/))&amp;quot; (both expressions correspond to the determiner &amp;quot;the&amp;quot; in most English contexts) is explained by using the memory structure model as follows: a referent of the noun modified by &amp;quot;sono&amp;quot; is found in tile discourse memory, and a referent of the noun modified by &amp;quot;ano&amp;quot; is found in the long-term memory.</Paragraph>
    </Section>
    <Section position="2" start_page="0" end_page="0" type="sub_section">
      <SectionTitle>
2.2 Basis for Memory Organization
</SectionTitle>
      <Paragraph position="0"> The memory is constructed by assembling three kinds of basic elements; 1) structure, 2) relation and 3) concept. Structure is a packet of memory organization. A variety of structures can be used to represent linguistic knowledge, the situation of utterance, and the meaning structure of a sentence. Concept is associated with structures which include all kinds of constituent structures; words, phrases, sentences, etc. Hence, this definition of concept, in a sense, is language-dependent. There are two kinds of concepts, semantic categories and word meanings. Thus a word and its meaning are strictly distinguished. Relation integrates structures to form a compomld structure. Examples of compound structures are compound norms, ease structures, and complex sentences. There are several kinds of relations such as casc relations, conjunctive relations and taxonomic relations between semantic categories.</Paragraph>
    </Section>
    <Section position="3" start_page="0" end_page="6271" type="sub_section">
      <SectionTitle>
2.3 Understanding Process
</SectionTitle>
      <Paragraph position="0"> In the understanding process, operations such as matching, searching, deletion, replacement, integration, and generation are executed in the memory structures. For example, in a morphological analysis process, using their literal expressions as search keys, the search for words to be identified is made using lexical entries in the dictionary, and in the case analysis process, a search is made for case instances that match prototype cases in ease frames.</Paragraph>
      <Paragraph position="1"> As understanding proceeds, the essence of episodic memory is assimilated into discourse memory and the essence of discourse memory is assimilated into long-term memory. Discourse memory (long-term memory) is not simply an accumulation of the contents of episodic memory (discourse memory), but is a structured memory coherently organized from the episodic memory (discourse memory).</Paragraph>
      <Paragraph position="2"> As a prelimlnary model of discourse memory, we define a Local Scene Frame (LSF), which is a collection of cases and predicates in preceding sentences already analysed. LSF is partly viewed as describing a  q Contextual structure ~nted case structure ntodel ~ F L ..... E11! PS i-s ...... / '.. _ _ _ Pr e2 up_p2 sitlon _ _ _ / q Complex Selltenco structure (Extended case structure model ) F r ............................... .</Paragraph>
      <Paragraph position="3"> t ........ _ _ _ c2~i2~2~t;2 ~_ ............ d -~ Unit sent ...... tructure F L cdeg_'~p-degu'~'Lndeg&lt;-'&amp;quot;- J \[ Y ,_,,b_o a_a~ a ~._o,_~t_~,_~_ \] ..... Simple sentence structure i L ~._. __t,_No_&lt;kqa_~__ J t ..... ...... ,,.uot .... 1/4</Paragraph>
      <Paragraph position="5"> Fig. 1 Extended Case Structure Model situation in which the utterance is carried out. Information in the LSF is used for filling in missing cases, and resolving anaphora. A discussion of the detailed procedure for the assimilation would be beyond the scope of this paper.</Paragraph>
    </Section>
  </Section>
class="xml-element"></Paper>