with the advent of cyberspace and development of data and information, virtual cities were presented as new forms of city management in different layers and territories. historic and tourism virtual city are among eight types of virtual cities. in this article some guidelines were presented in order to design and manage them based on tehran tourists' need assessment. theoretical framework ...

The management of urban sprawl is fundamental to achieving sustainable urban development. Monitoring urban sprawl is, however, challenging. This study proposes the use of two spatial statistics, namely global Moran and local Moran to indentify statistically significant urban sprawl hot and cold spots. The findings reveal that the Moran indexes are sensitive to the distance band spatial weight m...

Bitmaps are popular indexes for Data Warehouse (DW) applications and most database management systems (DBMSs) ooer them today. This paper analyzes query optimization issues for selection operations using bitmaps. Both continuous and discrete selection criteria are considered. Query optimization is categorized into static and dynamic optimization. The static optimization issues discussed are the...

We study the self-duality operator on conic 4-manifolds. The self-duality operator can be identified as a regular singular operator in the sense of Brüning and Seeley, based on which we construct its parametrizations and closed extensions. We also compute the indexes.