This paper describes the functions,characteristics and operating principles of search engines based on Web text,and the searching and data mining technologies for Web-based text information.Methods of computer-aided text clustering and abstacting are also given.Finally,it gives some guidelines for the assessment of searching quality.
The paper discusses the construction of a content based intelligent system that performs multimedia information filtering and retrieving on the Internet.The system disassembles the multimedia information into different media objects and describes them with vectors for content based retrieval.In the user study module,the system uses the BP neural network to clarify the user interests for intelligent filtering and retrieving.
The paper mainly deals with the basic concept,characteristics and methods of the color and shape based image retrieval.It gives several quantization algorithms for image retrieval.At the same time,Otsu method that selects the image threshold automatically and a new method using information entropy are described.
