Design And Develop Of The Distance Education Automatic Question-answering System Based On Distributed Technology

The rapid development of distance education promotes the progress of the distance education technology as the establishment of the concept of life-long learning; networked education plays an important role. Q&A has attracted increasing attention of educators, which is an important component in both teaching and learning. As a method of communication between the teachers and students,intelligent and efficient Automatic Question-Answering system not only resolve the doubts timely, but also reduce the cost of distance education effectively.Automatic Question-Answering system is the one of the advancest information retrieval system, which uses natural language processing technology, could answer the questions accurately that is set by user, compared to traditional search engines, it is better meet the needs of the user's search, users need to identify more precisely the answer. Automatic Question-Answering system is the field which is development research, at artificial intelligence and natural language processing.This dissertation describes the background and significance of Question-Answering system firstly, and then analyzes the researching status of it. According to the strengths and weaknesses of current Question-Answering system designed and implemented a Chinese Question-Answering system based on distributed technology. To direct at the application of distance education, the database of the answering system's knowledge must be massive, so the paper introduces the Distributed open source framework Hadoop to built the knowledge base .Considering the volume of users and system capability of load balancing , to improve the speed of retrieval by question sentence with parallel computation.For another key question of answering system:the computation of sentence similarity, this paper introduces a scalable method based on HowNet to improve the accuracy of answering.This system implemented four modules including Chinese words segmentation module, question understanding module, knowledge base index module and information searching module. Chinese words segmentation module is the basis of answer users' questions correctly; question understanding module involved classification of questions, key phrases extracted and extended; knowledge base index module constructed the index by Lucene; information searching module retrieved related issues by Chinese word segmentation technology, and then calculated the sentence similarity. Finally,this paper test the Automatic Question-Answering system which is show that has good precision and efficiency, it also meet the distance education requirements of answering and achieves the desired goal.