The JaRAP Experimental System Of Japanese-Russian Automatic Translation

The paper is the first report on the experimental MT system developed as part of the Japanese-Russian Automatic tra.aslation Project (JaRAP). The system follows the transfer approach to MT. Limited so far to lexico-morphologieal processing, it is seen as a foundation for more ambitious linguistic research. The system is implemented on IBM PC, MS DOS, in Arity Prolog (analysis and transfer) and Turbo Pascal (synthesis). 1 Theoret ica l background The development of the Jall.AP experimental system was preceded by a long period of purely theoretic research into various aspects of natural language ~'td its functioning in translatio~t (see, e.g., (Shalyaplna~lO80a,1980b,1988)). Some of the basic principles which have evolved from this research may be summarized ~m follows. (1) The most adequate scheme for simulating human translation ~ctlvity is doubtless the transfer one. (2) The level of transfer and the volume of structural and semantic information explicitly represented at this level should be determined experimentally as a compromise between the demands for translation adequacy under the given conditions and the advantages of "shortcuts" permitted by the superficial correspondences between the languages concerned. (3) Semantics is not in itself a level of linguistic representation, but rather part of linguistic description at any level of representation of linguistic units. (4) In its semantic aspects, syntax is dependent on lexicon to a greater extent than vice versa. (5) A model aimed at faithful simulation of linguistic performance should make explicit use of the factor of linguistic normativity, this being, at least in prospect~ a building block for "self-tuning" functions as an analogue for human learning capabilities. An approach best suited for effectuating these principles seeirm to be that of relying on a lexiconoriented lingware framework of a special kind. Within this framework, eTttrles of a uIfiform structure may be provided, besides lexlcal units, also for morphological categories, fanctlon elements (inchdlug punctuation), and all kinds of grammatical features, while syntagmatics of all levels may be presented in terms of valencies of those levels, assigned to the corresponding lexical or grasmn.atlca] units in their entries. The JaFtAP experimental system is meaatt to incorporate this approach. In ~cordance with the transfer scheme of translation, the system is made up of three major components: the Japanese analysis component, the Japanesc-Rl~ssian transfer component, and the Russian synthesis (generation) component. It is implemented on IBM PC, MS DOS, its programming tools being Arity Prolog for analysis and traamfer~ and Turbo Pascal for synthesis. 2 The current version of the J a R A P s y s t e m At present, the JaRAP system does not go far beyond the i~fitial lexico-morphological level of text processing (though some provision has already been made for further stages of its development see See.3). The analys is component of the system performs so far three main groups of operations: segmentation of the input Japanese texts into graphicomorphological (CAM-) elements (stems aJtd suffixes of Japanese words); processing s] tranMationally idiomatic (TI-) csm6inatisns of GM-elements; and lezieo-rnsrpholofical (LM-) analy~i.¢ of the resulting sequence of (]M-elements aatd the_Jr TLeomblnations. Segmenta t ion is accomplished in two steps. First, the input text (= the input sequence of k~na and kanjl kodes) is broken up into fragments by conteztual delimiters eertMn to denote word or morph boundaries (e.g., punctuation marks, the occurrence of a k~tat~na symbol after a hlragana one or vice verB% etc,). Then the fragmgnts obtained are segmented into GM-elements by mea~ts of dictionary