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Background: In this study, we clustered a large number of microblog users into city nodes based on the interpersonal relations and geographic location attributes of these users and clustered the user relations within each city into the relations among cities in the Wuhan "1+8" City Circle (WCC) to transform and map the interpersonal network in the virtual network environment to an intercity network. Methods: Based on this mapping, we analysed the characteristics proposed two evaluation indicators-degree of city cohesion and degree of city outreach-to quantify the relations within a city and the relations among different cities. The WCC urban network was analysed from a social network perspective, and the differences and similarities in a city's status between the virtual network and the real world were explored. Results: As the "1" in the "1 + 8" WCC, Wuhan's decisive dominance in WCC was discussed from multiple perspectives to show the centre point of the circle and the monopoly status of Wuhan in WCC. This finding is consistent with the status of Wuhan in the actual geographic space as the political, economic and cultural centre of Hubei Province. Our study indicated tiny communication among the other 8 cities along the periphery of WCC in the virtual microblogging network space, with the exception of Wuhan; they closely resembled eight independent individuals. Conclusions: The characteristics of the WCC intercity information exchange indicated that the concept of WCC did not stand out in the virtual microblogging network space and that these cities frequently exchanged information with cities outside WCC. And in WCC the degree of cohesion and outreach in a city node were significantly positively correlated with the economic development level of the city.

Symbol portrayal is an important function of GIS. Sharing symbolic information in different GIS platforms is necessary for GIS applications and users. This paper discusses the necessity, possibility and solution technique of sharing a symbol library in different GIS platforms. The route map is designed as follows: first, to set up a general data model for the symbol library, then to design a standard exchange format, and finally to call on the GIS manufacturer to provide the interchange tools for their symbol library for the standard exchange format. This paper analyzes the general characteristics of GIS symbolic library, gives a symbol library model and a draft of XML schema of the symbol library exchange format.

This paper gives out the framework of active cartography of statistical map, includes the structures of cartography language of statistical map, cartography model base of statistical map and cartography knowledge base of statistical map. In addition to the framework, this paper brings forth the renew mechanism of cartography knowledge and the conversion method from Natural Language to cartography language. In the last, this paper discusses the resources of the framework, analysis the user's service mode for cartography of statistical map, and introduces the ECA (Event-Condition-Action) principle to active cartography service. By the help of ECA principle, ordinary cartography users will be convenient when using the active cartography service of statistical map.

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