Through solving key techniques,such as CAD data s semantic translation,block library s communication with common map symbol library,and map symbol s display on multi-platform,synchronous transfer of block information into GIS format in the course of data conversion is realized,CAD block information sharing is achieved.

The translation is based on the semantic of source schema and target schema,and includes two phases: semantic translation and data translation.

Based on the study of the present state of GIS data conversion, the concept of Semantic Conve rsion is discussed, and a further inquiry is made into the technique about proceeding spatial data semantic conversion on the platf orm of Feature Manipulation Engine (abbreviate FME below).

For the low matching accuracy caused by heterogeneous information in content-based publish/subscribe systems,by defining the relationship among the attributes of events and subscription,a design method of semantics-supported publish/subscribe is proposed using the semantic conversion module.

Ttransformation idea of semantic conversion, Using GIS space data conversion are realized.

Form the perspective of semantics, GIS is a symbolic system in the logistical formalism, and GIS semantics can be understood as spatial conception represented by the GIS.