This paper presented a pre-fetching model based on concept association network, which mines a concept association relationship implied in user access patterns and employs online learning and offline mining algorithms to construct a user-oriented concept association network.

Aiming at automatic indexing and user s retrieval requests in information retrieval, a kind of concept space technology, concept association and concept cluster algorithms based on hopfield neural network are introduced in this paper.

In this paper,a neural network approach to constructing concept association of Chinese information is shown.

This paper introduces the concept definition and developing situation of nanometre, and puts forward the right attitude to welcome the nano-times.

Moreover, we considered several problems in concept definition and methodology concerning time perspective.

Concept definitions serve as the foundation of mathematics, but they do not derive directly from the objective reality and have the multiple characteristics of abstractness, generalization and simplicity, thus, it is difficult for students to recite concept definitions without omitting a single word.