A Triptych Software Development Paradigm - Correct System Design: Recent Insights and Advances - page 48

Federation means that data may reside on dierent GIS, DIS, etc, platforms:
commercial, experimental, public domain or otherwise: APIC, ArcInfo, MapInfo,

IDRISI, PopMap, Redatam, winR+/GIS, etc.

6.3 A Third Narrative

Geographic, Demographic and other Data | Data: We now describe, more gener-
ally, but still informally, and from a slightly dierent viewpoint, the components
of the proposed federated GIS+DIS. The base information unit, which usually
is a highly composite entity, will be referred to as `Data'. Examples of specic
data are:

Examples 6 A Geodetic Map of China, A Political Map of Europe, A Vege-
tation & Natural Crops Map of GuangDong Province (in China), A Mineral
Deposits Map of France, A Spatially related Population Census of Zhuhai 4 ,A
Cartographic and Cadestral Map of Macau, etc.

Domain Names: By D we understand the set of domain names:

Examples 7 China, GuangDong, Zhuhai, . . .

Data Category Designators: By C we understand the set of composite data
types:

Examples 8 Geodetic Map, Political Map, Vegetations & Natural Crops Map,
..., Cadestral Map, Population Consensus Data, Import/Export Statistics, ...,
Election Data.

Version Identiers: By V we understand the set of version designators (time
stamps) of data:

Examples 9 1982, 1996, ..., September 21, 1999, . . .

The Database: Data is kept in a conceptual data base (DB). The data base, as
we shall see, can be interpreted as being distributed globally. Each data has a
location (L).

Hierarchical Directory Structure: A (d,c,v) identication designates (geographic
(GIS), demographic (DIS) and other) data in a hierarchical fashion. Assume xed
type and arbitrary version, then the domain name China could, for example, give
access to some data on all of China and then to a set of properly domain-named
sub-data of the same (and also other) type(s), etc. One for each (, say) Province
of China. And so on, recursively, until some user-dened \smallest grain of data"
| which could be a floor plan of a specic residence, a single plot of land for
4 Zhuhai is a Special Economic Zone of GuangDong Province in China