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Title
The 3rd ISPRS Workshop on Dynamic and Multi-Dimensional GIS & the 10th Annual Conference of CPGIS on Geoinformatics
Author
Chen, Jun

ISPRS, Vol.34, Part 2W2, “Dynamic and Multi-Dimensional GIS", Bangkok, May 23-25, 2001
124
4. Dynamic Management Spatial-Temporal
Information System "DyMSIS"
DyMSIS was created by converting the DiMSIS data structure
proposed in [1] to KIWI+ format, and can be considered the
successor system to DiMSIS. DyMSIS has the constitution
shown in Figure 3. 1 2 3 4 5
Application Subsystei
A
^ Core Subsystem ^
f
AS
Attribute
Database
V
Geographic Data
(KIWI+ format)
V
Initializing
Information
Vectors Connectors
Figure 3. System Constitution
(1) Geographic data comprised of vectors and connectors
(KIWI+ format)
(2) Core subsystem that executes management, plotting, and
search of geographic data
(3) Initializing information including feature space definitions
(4) Application subsystem that constructs a GUI and refers to
and renews the attribute database
(5) Attribute database related to connector information
5. Spatial Temporal Analysis
5.1. Concept
By means of spatial temporal data management, analysis using
temporal factors (spatial temporal analysis) becomes possible.
When such analysis is performed, the comparison of information
between two specified time points becomes an essential function.
It is possible to observe changes in feature space regions
(points, lines, areas, volumes) between two time points by
overlaying map data for the two time points (Figure 4). However,
in general, in order to track changes in all map data for the two
points, a considerable amount of time is required for this
operation. In order to reduce the time required, we propose the
method of calculating data corresponding to the overlay results
prior to data input. With this method, as for comparison between
two time points, if the types of data overlaid are the same and
known, the method is considered effective.
Figure 4. Overlay of data for two time points
5.2. Algorithm for calculating differentials between two time
points
Inputs and outputs of the algorithm for calculating changes in
area between two time points are as follows (Figure 5).
Inputs:
[Positional information]
Representative point P identifying the target region of feature
space.
[Feature space information]
Feature space D defining the target region of feature space.
[Temporal information]
Time point (T) used as reference for comparison of temporal
information (T,T).
Outputs:
(1) Representative point Q (one point) identifying region of
feature space at time point used as comparison reference.
(2) Representative points Q'1 - Q'N (N points) identifying region
of feature space at time point used as comparison target,
and feature space region comparisons R'1 - R'N between a
feature space region and parts of feature space contained in
a comparison reference region within that region.