Research On Method Of Acquiring Commonsense Knowledge Based On Semantic Taxonomy

On the basis of dynamic semantics, the thesis uses semantic, grammar and commonsense knowledge as the standard to classify the various semantic phenomena in the real world into various semantic classes, and construct a multi-level semantic taxonomy which can be utilized to extract commonsense knowledge and axioms of these semantic classes.All semantic phenomena are divided into two broad categories, namely event semantic classes and state semantic classes, which are both represented by frames. To demonstrate the practicability of our semantic framework and method, we use the typical "transactional" class as an example to explain the method of commonsense knowledge acquisition and axiom acquisition.The contributions of this thesis are as follows.1. Developed a framework to describe the semantic phenomena. The content of a semantic class includes definition, relationship, semantic grammar, predicate representation, commonsense knowledge, and example sentences. Relations between two semantic classes includes hypernymic, temporal, causal, synonymic and antonymic relations..2. Designed a grammar to recognizeor parse sentences with asemantic class. In the semantic framework, a grammar consists of a special kind of semantic productions.The right-hand side of a semantic production is a sequence non-terminals of the form<semantic role:type>, where<semantic role> includes agent, patient, location, etc., and<type>indicates what type(s) of things can play the semanitc role.3. Set a few guidelines of semantic classification. Different semantic classes have their own unique semantic features, emantic classes expressed indifferent ways represent different meanings.Similar semantic classes have similar senses. Therefore, we classify semantic phenomena based on semantic, grammar and commonsense knowledge into a semantic framework.4. Introduced a few methods of extracting the commonsense knowledge buried in semantic classes. We proposed some ways to extract the commonsense knowledge about semantic classes; namely,extracting commonsense knowledge in the semantic framework, extracting commonsense knowledge based onthe meaning of semantic classes, extracting commonsense knowledge with the semantic roles, extracting commonsense knowledge from the relationship between semantic classes, extracting commonsense knowledge by example sentences, and extracting commonsense knowledge through several commonsense perspertives.5. Explored methods of obtaining axioms of semantic classes. We designed ways to obtain axioms about semantic classes;namely, designing axioms about the semantic roles, designing axioms from the relationship between semantic classes, designing obtain axioms in the combination and pseudo combination of semantic classes, designing axioms by refining semantic roles, and designing axioms through analyzing the situations where semantic classes may occur.