The Application And Research Of Mobile Agent In Distributed Information Retrieval

At the present time, people usually search information on the Internet by search engine technology, which is based on www information processing system, it resolves some questions about searching information on the www in a certain degree. But current information is stored on heterogeneous,distributed,complicated network environment. The traditional information retrieval system shows clearly following problems: firstly, the information-overloading brings the lower efficiency issues. The recall ratio of the traditional retrieval technology is not high, even though users can get a lot of information by it, these information maybe be not useful for users, sometimes users have to sift useful information from a lot of information, wasting a lot of time and energy .secondly, system is dependent on bandwidth highly, it is very easy to cause network congestion. The traditional information retrieval pattern is based on C/S pattern, it is necessary to keep the steady connection in the services, which can cause the waste of bandwidth. Thirdly, it lacks some certain intelligence. In addition, it also exists for some other questions, for example, its safety is not too high, its mobility is not good, and its results lack real time and so on.Mobile Agent is the combination of Artificial Intelligence and Distributed Computing, because of the characteristic of mobility,independency,coordination, it has applied in distributed system extensively, and demonstrated huge prospect and superiority. The main purpose of this thesis is to explore a kind of distributed information retrieval pattern based on mobile agent, improve efficiency of information retrieval, reduce the dependency between system and bandwidth, and realize information retrieval intellectualization. So that it can solve the traditional information retrieval low efficiency,poor safety,low intelligence issues.Firstly, this thesis analyzes the relative technology of traditional distributed information retrieval, especially for the technology of search engine, analyzes the disadvantages and advantages of it ; Secondly, it elaborates system structure of mobile Agent and key technology, in comparison with other distributed computing technology, it probes the superiority of mobile agent technology applied in distributed information retrieval; Thirdly, it has designed a distributed information retrieval model based mobile Agent, elaborated its function and system operational mechanism, and it has also given solution scheme of key issues, these key issues mainly contains migration mechanism of mobile agent,fault-tolerance mechanism of system,congestion of results,safety problem and so on; Finally, using Aglet as development platform and java as development language, we implemented the mode simply.