G-TERD
Generator for
Time-evolving Regional Data
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Last update: June 12, 2002
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1. Overview
G-TERD is a novel approach for data generation, which is specifically
designed for applications stemming from the field of time-evolving regional
data. The basic concepts that determine the function of G-TERD are the structure
of complex two-dimensional regional objects, their color, maximum speed, zoom
and rotation-angle per time slot, the influence of other moving or static
objects on the speed and on the moving direction of an object, the position and
movement of the scene-observer, the statistical distribution of each changing
factor and finally, time.
G-TERD is a software tool highly parameterized so that different parameter values may produce spatio-temporal data set distributions with different characteristics. Experimenters may control the behavior of the generator by defining parameters and statistical models. Such an approach considers the characteristics of a wider range of applications.
Experimenters may specify the time domain and the length of the size of the workspace, the maximum number of objects in the sample, their minimum and maximum speed, zoom and rotation-angle per time slot, the percentage of static and moving objects, and finally, the length of the field of vision of the scene-observer and the number of colors it supports.
Experimenters may also decide about the statistical model that should follow the number of new objects and sub-objects per time slot, the deletion time slot of an object or sub-object, its speed, zoom and rotation-angle per time slot, and finally the period of time that must elapse before the next computation of an attribute such as the color, speed, zoom of an object or sub-object, etc. Various statistical distributions are supported for that purpose.
G-TERD allows experimenters to compose many different individual sub-scenarios and it can conjuncts them by merging the resulting data sets.The Web site of G-TERD provides access to the generator and its source code. Therefore, future researchers have the ability to adjust the algorithm of the generator according to different classes of spatio-temporal database application requirements and to produce sample data sets for their own needs.
a) G-TERD
The source
code of G-TERD was written in C language under the platform of Microsoft
Developer Studio 97 (Visual C++ 5.0). Experimenters may download the source code
of G-TERD with succinct description of every routine in it.
Experimenters may
use the
executable file 'g_terd.exe' of G-TERD in order to produce their
own synthetic time-evolving regional data sets. Experimenters may set the
user-defined parameters and statistical models through the file:
'inputs.txt'. After running the executable file of G-TERD, some new
files will be created in the working directory:
- the files
"Im*.col" which are the resulting multicolored images (the
time-evolving data set),
- the file "log.txt" which reports the
messages that appear on the screen,
- the file "errors.txt" where
experimenters may find some help, in cases where G-TERD can not be executed
because of a wrong setting of the user-defined parameters,
- a new directory
called "visual" which contains files that will be used by the
visualization tool,
- other not important files.
b) Visualization Tool
The visualization
tool is based on Gnuplot 3.7 for Microsoft
Windows. Experimenters may use this tool to visualize their own resulting
regional data sets by calling the file:
'visual.exe'.
Precondition: the visualization tool has to be
decompressed and run in the directory where the executable file of the G-TERD
is. Otherwise: an error message is printed.
On the moment the visualization
tool supports only ten colors to visualize.
c) Example data sets
Five sample
time-evolving regional data sets are offered. The corresponding scenarios
and the values of the user-defined parameters and statistical models are
described in Section 6 of the Technical Report of G-TERD. Experimenters may
visualize these demo regional data sets by calling the file
'demo.exe'.
Precondition: the compressed file of the example
datasets has to be decompressed and run in the directory where the executable
file of G-TERD and the visualization tool is. Otherwise: an error message is
printed.
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T. Tzouramanis, M.Vassilakopoulos and Y. Manolopoulos: “ On the Generation of Time-evolving Regional Data”, Technical Report, Data Eng. Laboratory, Dep. of Informatics, Aristotle University, Greece, 2001 (GeoInformatica, in print). |
or contact with T. Tzouramanis, M.
Vassilakopoulos or Y. Manolopoulos. 4. Files to Download |
Executable file of G-TERD (last update: March 7, 2001) |
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Source code of G-TERD (last update: March 7, 2001) |
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Visualization tool (last update: March 7, 2001) |
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Sample data sets (last update: March 7, 2001) |
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Samples of color images created by G-TERD (last update: June 12, 2002) |
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Directions for use: please read carefully the .TXT files that can be found in each of the above compressed files. |
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© 2001 DELAB AUTH. All rights
reserved. Last update: 12/06/2002 Webmaster: Theodoros Tzouramanis |