A realization for virtual sound source was presented based on a study of sound source positioning principle.

In order to improve the efficiency of on-the-spot test and accuracy of the data, the authors proposed a new method to set up virtual noise sources based on the noise decay principle.

Virtual sound and its application;

Simplification and subjective evaluation of filters for virtual sound using loudspeakers;

The defects of the traditional virtual sound with two loudspeakers and current virtual sound with four loudspeakers are analyzed.

A path following method is introduced with virtual sonar s model which originates from the behavior of human beings.

The flow of virtual resources hidden in grain trade is another important allocation form of water resources since 1990,besides the allocation form of supply and demand side and of basin redeployment.

This paper introduces the present situation of university library, expounds the contents of actual resources and virtual resources and the methods for acquiring actual resources and virtual resources, and elaborates the relation between actual resources and virtual resources.

This paper expounds three main integrating methods taken by network information resources in libraries, and probes into the countermeasures for strengthening construction of virtual resources of key subject in the university libraries from aspects of strengthening construction of database, establishing the navigation pool of key subject, providing individualized information services, etc.