Syntactic-Semantic Analysis Of Ancient Chinese Based On Database Semantics

The current natural language processing of Chinese is mainly concerned with modern Chinese. However, ancient Chinese is also a carrier of traditional Chinese culture. Automatic syntactic and semantic analysis of ancient Chinese is significant to the introduction of traditional Chinese culture into the world. The automatic syntactic and semantic analysis of ancient Chinese will also promote that of modern Chinese.Though the automatic syntactic and semantic analysis of modern Chinese has made a lot of progress, the commonly applied grammars and the existing parsers are not satisfactory when applied to ancient Chinese syntactic and semantic analysis. Supported by the theory of Database Semantics, this research is based on Left-Associative Grammar. Following the principle of time-linearity and description, this research is conducted on the basic syntactic and semantic relations in ancient Chinese with the original text and the English translation of Zuo Zhuan as corpus. This research is composed of the following parts.First, we have extracted data from the bilingual corpus, self-made with the original text and the English translation of Zuo Zhuan, to build up a lexicon, which meets the demand of Database Semantics-based syntactic-semantic analysis. In the lexicon, a word is stored as a "proplet" that is a non-recursive feature structure, i.e. a set of attribute-value pairs. Values of the attributes in a proplet represent the lexical information and semantic information of the word. As required by the syntactic and semantic analysis, this kind of data structure helps to reduce ambiguity caused by polysemy and temporary shift of part of speech.Secondly, we have generalized the grammatical features and sentence patterns of Zuo Zhuan from the perspective of natural language processing and composed basic syntactic-semantic rules to facilitate our syntactic and semantic analysis based on Database Semantics and Left-Associative Grammar. Our analysis covers the structures of subject-predicator, coordination, predicator-object, etc, as well as the variants of these basic structures, including object-fronting, semantic passive, formal passive, element omission and so on, within the fundamental application scope of nouns, verbs and adjectives.Thirdly, we have proposed the algorithm of conditional transplantation regarding function words and other words in auxiliary position. In the absorption of a function word by a content word, the core value and/or the semantic value of the function word is maintained under certain conditions. As different from the complete absoption in the original Database Semantics, it helps to avoid possible backtracking to a large extent in later language production and machine translation.Fourthly, we represent language content rather than superficial structures in the derivation. We analyze deep-level semantic relations and pragmatic meanings, which are then represented as new values of the semantic attribute of of the corresponding word. The additional values, such as agent, patient, experiencer. passive, rhetorical, are provided during the rule operations to indicate semantic roles and pragmatic functions.We expect larger-scale application of the automatic syntactic-semantic analysis based on the improved Databse Semantics, for example, to ancient Chinese texts that are produced in a different era and therefore have different features from that of Zuo Zhuan. Language production and machine translation based on this research may also be a focus of our future research.