Study On The Event Extraction Of Questions In The Geography Question And Answer Of College Entrance Examination

Event extraction is an important research content of information extraction.The open domain knowledge association and key technology index system and reasoning and the National 863 project,in order to achieve an intelligent answering system of geography as the goal,the question of information extraction is an important research content,through artificial analysis found that the characteristics of geography quiz questions are:most of the questions provided to understand all the questions last the information required;the form of questions has certain modes;and the question contains information on geography knowledge.In this context,this thesis studies the extraction of events from the questions of geographical questions and converts them into the form of problem-solving templates.The contents of this thesis include:(1)analysis of the geography for many years questions,combined with experts in the field are summarized and the cluster analysis method,including the definition of geography questions the type of event and event elements.(2)using a combination of event trigger method of support vector machine for event type recognition of the test questions in the event.(3)geographic events using maximum entropy model for event element recognition of geography exam in the event,using the method of syntactic dependency relations and vocabulary based on problem of event element event event element recognition.The main achievements include:(1)The geography questions in the event is divided into events and geographic events,according to the questions and solving problems of template event types are defined,combined with the geography textbook chapters through the cluster analysis method,the definition of geographical event types.The problem,event element and geographic event element are defined according to the problem solving needs and the characteristics of the event itself.This thesis gives the analysis of location factors such problems of agricultural events,events and the layered modeling method of transport geography three representative events,provide a reference for other geographical questions in event modeling.(2)A method of event type extraction based on support vector machines and event triggered words is proposed.Because of the geography college entrance examination questions the existence of small categories of event data lack of data sparse problem,this thesis first use the classifier to recognize the geographic events of its geographical event parent types,based on trigger words recognition of its geographical incident atom types.Experiments show that the method can improve the accuracy of event extraction,and make up for the small amount of data and sparse data of small class of geographic events.(3)Using the maximum entropy model,the event elements of the geographical events in the examination questions are identified,so that the extraction of the elements of different types of geographical events is easy to transplant.For reasons of single sentence form,using the method of syntactic dependency relations and vocabulary based on problem of event element event event element extraction algorithm,strong interpretability,easy realization does not require a large amount of corpus.(4)A comprehensive experiment of event extraction is designed.Implementation:enter a question question section of the geographic question,output all event types and corresponding event elements.Through comprehensive experiments,on the one hand,the overall effect of event extraction system is detected.On the other hand,the output of event extraction integrated system can be used to transform the input of the question answering system of the college entrance examination question answering system.