The Research And Implementation Of The SOST Framework For P2P Info-Sharing

The Internet technology is developing rapidly and information resource is following an exploding trend. The need of digital information is growing, however, currently, some of the information resource are not being used to its full extent. It has become a widely concerned issue on how to maximize the utility of information resource and share it with the help of modern information technology.The view of modern researches is that while the traditional C/S structure can provide a centralized information sharing, due to its character, the bottle-neck of network bandwidth and system performace is becoming conspicuous. The general acceptance of information sharing applications like Napster and Gnutella is attracting attention on P2P (Peer-to-Peer) information sharing technology. P2P information sharing can efficiently prevent the performance bottle-neck in C/S structure and fully utilize the information resource situated on peers at the edge of the network. Although the current technology can reach a certain point in P2P information sharing, it still seems that from a view of information retrieval and P2P network topology, it still has limitations in search effect, search quality and system scalability, and it is costing too much for the search.Aimed at resolving these problems, we experimented the SOST (Semantic Overlay and Searching-Tree based) P2P information sharing realization framework. The framework is composed of P2P Layer and Semantic Layer. The P2P Layer uses ILRBTree (In-Layer Recommend-based Binary Tree) algorithm to organize information resource and it efficiently solved the key problems in low scalability, low routability, high search cost and complicated structure maintenance; Semantic Layer provides semantic support for information description, and it brings up SMQE (Semantic Multiple Query Expansion) technology to realize query extension so as to efficiently solve the problems in search effect and the limitation on search quality.By using SOST P2P information sharing realization framework as guidance, we built a prototype system of SHAREPEER and tested the framework. The test results show that SOST-based info-sharing system achieves high search quality, high system scalability, low search cost and very convenient maintenance.