Conceptual Network Technology Applications And Research, Information Organization And Information Retrieval Of The Digital City

Information construction and Information retrieval in digital city is important research in the field of digital city, and whether users (include government, enterprises and common users) approve the digital city project is decided large partly on it. In this thesis, we analyze the system structure and technology strategy of the current digital city projects, and study the complicated relations of information about these systems, and also point out some limitations about the information construction and the information retrieval in the current systems. A best information construction is the base of an effective information retrieval. Based on it, the thesis brings forward information construction and information retrieval based on conceptual network.Aiming at the concept representation, the thesis gives the model of the conceptual network, which expresses the connotations of concepts based on Object Oriented method, assuming that a concept is a complicated object which has attributes, behaviors, concept descriptions, concept words. By the relations of construction and semantics, the concepts between each other can construct a complicated conceptual network. By the network, the knowledge between each other forms an associative grain and reasoning principle.Aiming at building the conceptual network, the thesis gives a technical route that is from the concept nodes to concept trees by classifying, and then from the concept trees to the relations of the concepts to form a conceptual network by analyzing the model of the concepts and their characters. After that, we used this technical route to the information construction of the digital city, and achieved the conceptual network of digital city.On the information retrieval, we also give three methods of information retrieval in conceptual network, and mainly discuss the method based on concept calculation. In the thesis, we define a set of concept calculating methods about conceptual network. By vectoring concept model, and calculating users' interests on querying intention, we extract some conceptual sets in conceptual network. In the conceptual sets, we can get the best matching result by concept calculating and concept matching on querying intention. To some querying, which need to get the relations among the concepts, this thesis borrows optimal path algorithm in the graph theory, and also gives the sub-optimal path algorithm to retrieve information based on the optimal path algorithm.At last, the thesis exposes the system realization, and analyzes the construction of the system and the relations of each part. Information construction and information retrieval based on conceptual network provides a new solution for information construction of digital city, and also basically solves the problem of information retrial based on concept in digital city projects.