Research On Information Integration Technology In The Environment Of Peer-to-Peer Network

Information is the most important and target resources for people get by computer. With the rapid development of information and network technology, there is a great demand for a fuller share of information resources and a more efficient way to obtain and utilize them. At present, the mode of using information is multi-user and multi-source instead of single-user and single-source. "Informational Integration" has been one of the hottest technologies in the field of information technology, but the present system and technology can not meet the growing needs for the share of information. The mainly problems are as follows:·Specific Information Integration. Up to now, the research background in "Information Integration" directs mainly at the utilizing between particular systems, or between particular data types in particular area.·"content as centre" Information Integration. It is mostly based on the model of content as center for Information Integration over Internet, and the "edge resources" is hardly being used .·Passive and unattached Information Integration. Shared information is offered according to the interests or concerns of the publisher, so the information is unattached and sporadic, and the share of users is completely passive and blindness.Aim at these problems, the paper discusses non-specific Information Integrate technology in a more open environment, and provides new solutions to "Information Integration".The research in this dissertation is focused on the key technology of information integration in the environment of peer-to-peer distributed network, and summarizes the research findings of the author in this field. It researches on the architecture and organized mode beginning with the peer-to-peer network. And an overlay network suitable for information integration is designed as well as the information model and communication protocol based on it. Besides, the information security and credit is analysed, and a model of evaluating information equivalent exchange based on credit is proposed.The thesis describes the research works in detail, the principal contributions of the work presented in this thesis are:1) Research on the architecture and structure mode of peer-to-peer network. Analyzed node managing and suitable application, especially the key technology of message distributing application based on P2P. An information sharing architecture based on P2P ~ ICover is designed and its layer model is proposed.2) Analyzed the feature of information sharing in the environment of P2P, network node and information source were separated, three kinds of information object are defined : ICover node, source information and information item. A multi-schema driving information model rdfIM based on RDF is proposed. This design can meet the needs of distributing and autonomous node information describing in the environment of P2P.3) Research on the ontology mutuality technology. With the help of it heterogeneity of data source can be solved to a certain extent. An application domain ontology - iOntol is defined which is used to cope with the connection of information and its relation with the feature of variability, multi-layer and multiple description. A reasoning mechanism is proposed based on ontology similarity and fuzzy logic. And a searching mechanism is introduced based on ontology according to the tips above.4) Research on distributed searching technology. A global/local dual distributed searching mechanism is proposed based on theme and a concept of virtual routing table which can index the message distributed by the shared documents of all the nodes in ICover linked with theme, and form some subset of main directory stored on different ultra-node according to the theme. This mechanism can increase the rate of searching information. A distributed searching Policy is proposed based on information cost.5) Focused on equivalent exchange between information trust and information. The concept of asynchronous information equivalent exchange is introduced, information trust and node trust are defined and information equivalent model in ICover is designed. Asynchronous information equivalent exchange model DIexcher is introduced based on trust as well as a rate evaluating algorithm and a distributed information exchange rate management mechanism put forward. It is hoped that the equivalent information exchange management mechanism can be a certain kind of incentive mechanism which can encourage more user to become information supplier. This can expand sharing information source and make up a information sharing fare mechanism.